Research on Education for Sustainable Development with Design-Based Research by Employing Industry 4.0 Technologies for the Issue of Single-Use Plastic Waste in Taiwan

Abstract

The social impacts of prevailing circular economy (CE) strategies remain under-researched despite the considerable attention that CE has received from scholars and in industry. Existing CE indicators primarily focus on business models from a decision-making standpoint, overlooking consumer engagement and alternative solutions. Boasting one of the highest recycling rates globally, Taiwan faces challenges in optimizing collected resources. This study delves into recycling plastic waste by integrating consumer behavior within CE strategies, leveraging open-source resources and additive manufacturing technologies to align with the United Nations Agenda 2030, particularly Sustainable Development Goals (SDGs) 4 (Quality Education), 12 (Responsible Consumption and Production), and 13 (Climate Action). These resources facilitate the transformation of plastic waste into reusable materials. Employing an exploratory and participatory action research approach, this research uses the Precious Plastic Universe (PPU) database to identify potential resources from post-consumer polymer waste. Subsequently, it explores tools for converting collected waste into usable polymers. Lastly, the study investigates integrating collected polymer waste into student design projects to enhance creativity and problem-solving skills for sustainable development, employing additive manufacturing tools at the National Taiwan Normal University Department of Design. Thematic analysis of the data revealed several recurring patterns, including the role of consumer behavior in plastic waste generation, the development of creativity and problem-solving skills among students, and the challenges of working with recycled materials. These themes were observed in quantitative data (collected single-use polymers) and qualitative insights from student observations and interviews. Through thematic analysis, the study highlights key factors contributing to successful CE integration, providing a model for future educational and industrial applications of sustainable design.

1. Introduction

The importance of sustainable practices has spread widely to many disciplines, such as academics, industries, and policymaking, in the past decades [1]. In this context, the United Nations Agenda 2030, with its 17 Sustainable Development Goals (SDGs), serves as a global blueprint for achieving a better and more sustainable future for all [2]. Regarding sustainable development, it is urgent to discuss the economic system since we have relied on the consumption-based linear system in past decades [3]. While the past decades’ economy refers to a linear economy, the European Union (EU) proposed the circular economy action plan (CEAP) to address elongating the product lifecycle to reduce the impact. The EU’s CE approach is to create a system for easy repairing, more sparing parts, facilitating end-of-life treatment, and establishing standards [4]. Furthermore, polymer waste is collected and used innovatively to reduce the consumption of natural resources [5].

Currently, the circular economy (CE) is receiving more and more attention from scholars and industries. Geissdoerfer looked at peer-reviewed articles on this topic and indicated a significant increase in the past decade [6]. Furthermore, Dzhengiz et al. argued that the circular economy is in danger of being perceived as a vague concept with poorly defined boundaries and unclear definitions, with rapidly increasing research in recent years [7]. Kirchherr summarized 114 CE definitions to create transparency regarding the currently understood CE concept through screening related articles [8]. The researchers pointed out that there have been different recognitions in CE core principles when classifying CE strategies. To express the key CE idea (Figure 1), the nine Rs (reduce, rethink, reduce, reuse, refurbish, remanufacture, repurpose, recycle, and recover) represent the degree of circularity to these products. Braungart and McDonough noted that most recycling is downcycling; it reduces material quality over time. The authors also pointed to rethinking the production/distribution and consumption process before recycling by reorganizing the waste hierarchy [9].

In the investigations for defining CE, researchers agree with the definition provided by the Ellen MacArthur Foundation [10]. The definition has promoted many business sectors to incorporate the basic concept of CE. Lewandowski claimed that circular business models often appear at the core of CE [11]. CE business models consider the most in production and distribution but not consumption patterns. Ghisellini noted that “the promotion of consumer responsibility is crucial for CE” [12]. Lieder and Rashid also highlighted that supply chains need to consider consumption processes [13]. Gallaud and Laperche mentioned that the balance between consumer patterns and circular business models is the key to CE strategies [14].

CE defines replacing the ‘end-of-life’ concept with the frameworks of production/distribution and consumption processes (reducing, reusing, recycling, and recovering). However, recycling and recovering, for consumers, is the same act as throwing away trash [8]. This is one of the reasons why these two frameworks consider the linear economy. The most the consumer can contribute to this phase is separating the trash into different types. In big visions of CE, recycling is still part of the circular system. However, promoting recycling does not help implement the CE frameworks in our social mechanism. Most consumers have no choice but to throw trash into recycling bins. This research hypothesizes observing the consumers’ reactions when they have other opportunities than recycling their daily waste.

This research aligns closely with several Sustainable Development Goals (SDGs), specifically SDG 4 (Quality Education), which focuses on training students in sustainability literacy; SDG 12 (Responsible Consumption and Production), which advocates for the sustainable management and efficient use of natural resources; and SDG 13 (Climate Action), which highlights the necessity of combating climate change and its effects. Additionally, this study examines how integrating open-source resources and additive manufacturing technologies within a circular economy (CE) framework can enhance responsible consumption and production patterns in Taiwan. By focusing on the recycling and repurposing of single-use plastic waste, this research contributes directly to the global efforts of achieving the UN’s SDGs, providing innovative solutions that adhere to the principles of sustainable development.

Furthermore, this study explores how design students can incorporate sustainability principles into their work through real-world applications in their National Taiwan Normal University graduation thesis projects. By embedding CE strategies into their thesis work, students can engage deeply with sustainability issues, particularly emphasizing plastic waste reduction and innovative design solutions.

2. Research Background

2.1. Recycling Challenge in Taiwan

Based on data from the Taiwan Ministry of Environment, the amount of municipal waste generated on the island will reach over 11 million tons by 2022, and this has constantly increased in the past decade (

Table 1. Generation and treatment of municipal waste in Taiwan between 2017 and 2022.

Period	Amount of Municipal Waste Generated (Tons)	Amount of Municipal Waste Treated (Tons)						Amount of Municipal Waste Generated per Capita per Day (kg)
		Total	Recycling and Reuse		Incineration	Sanitary Landfill	Others
			Recyclable Waste	Food Waste
2017	7,870,896	7,870,896	4,188,829	551,332	2,993,435	70,382	90,699	0.915
2018	9,740,671	9,613,982	4,828,340	594,992	2,969,654	87,251	-	1.132
2019	9,812,418	9,650,074	5,023,517	498,045	4,042,110	86,402	-	1.139
2020	9,869,675	9,703,702	5,278,079	529,567	3,789,352	106,703	-	1.144
2021	10,049,062	9,898,071	5,666,869	482,105	3,501,983	247,114	-	1.173
2022	11,238,654	11,174,400	5,950,352	488,747	4,430,942	200,080	104,278	1.320

Source: Taiwan Ministry of Environment.

). Taiwanese recycling and reused wastes are over fifty percent of treated waste, contributing to Taiwan having the world’s fifth-highest recycling rate, according to the European Environment Bureau (EEB) [15]. However, Taiwan faces some challenges concerning plastic waste due to the increasing amount generated.

Table 2. Composition of municipal solid waste in Taiwan between 2017 and 2022.

Period	Total	Physical Composition (On Dry Base)
		Combustibles								Incombustibles
		Sub-Total	Paper	Textiles	Garden Trimmings	Food Wastes	Plastics	Leather & Rubber	Others	Sub-Total	Iron	Other Metal
	%	%	%	%	%	%	%	%	%	%	%	%
2017	100	97.52	36.12	4.63	1.55	38.14	16.00	0.43	0.64	2.48	0.21	0.28
2018	100	97.52	35.64	4.93	3.27	34.48	17.79	0.84	0.57	2.48	0.37	0.20
2019	100	91.13	38.83	5.10	2.42	31.12	18.67	0.55	0.43	2.87	0.39	0.26
2020	100	97.25	34.61	8.55	5.22	21.78	20.20	1.05	5.84	2.75	0.51	0.38
2021	100	96.62	37.26	7.63	3.19	17.63	26.28	0.86	3.78	3.38	0.65	0.42
2022	100	97.61	36.60	9.74	3.45	15.80	28.40	0.80	2.82	2.39	0.54	0.26

Source: Taiwan Ministry of Environment.

shows how plastic waste volume has constantly increased in recent years. Single-use plastics significantly contribute to plastic waste and are an urgent environmental concern. These plastics include plastic bags, straws, water bottles, and food packaging. In 2018, the EPA announced plans to ban these products, but no exact replacement has been identified yet. There are some difficulties in utilizing recycled plastic materials: the quality of plastics, lack of protocols, and lack of examining facilities. These single-use plastics are difficult to replace [16]. Several manufacturers, such as textiles and fabrics, focus on utilizing recycled plastics in Taiwan. It encourages these manufacturers to search for more discarded plastic products. However, whether implementing these products will support CE in society is still being determined [17].

2.2. Circular Economy (CE) Indicators

Moraga et al. investigated the development of circularity indicators based on the in-use occupation of material to assess the different product cycles [18]. They aimed to create a more effective evaluation of CE strategies with the product’s lifetime. Bocken et al. discussed categorizing CE strategies into two groups showing and closing resource loops [19]. The first group includes reuse, repair, or remanufacturing to delay the end-of-life phase of the product. The second group is end-of-life, such as recycling and recovering. The researcher discussed that although the timeframe is critical in these groups, many CE indicators often disregard it. One of the few CE indicators incorporating time factors when using materials in products is the Material Circularity Indicator (MCI) of the Ellen MacArthur Foundation and the longevity indicator [20]. This fact makes these two indicators relatively reliable. However, the research also points out that the MCI indicator mainly helps company decision-making in the design phase of products from the company’s perspective [21].

Although there is much focus on policies aimed at production processes, the role of consumers in circular economy strategies needs to be better understood [22]. Therefore, there are opportunities for empirical research to gain insights into consumers’ perspectives and responsibilities [23]. In the social recycling mechanism, consumers are responsible for separating their trash into different types. Additionally, the repurposed collected resources are only treated in the industrial sector. However, to enhance the definition of the circular economy and replace the concept of ‘end-of-life’, it is necessary to change consumers’ mindset from considering waste to collecting resources [24]. This research aims to delve into waste disposal and the role of creativity in shaping consumer behavior and employ it in a real-world educational context. Furthermore, this study observes how consumers react to different waste disposal alternatives and whether creative solutions can impact their decision-making with the available technologies. Dantas et al. described the implication of combining CE and Industry 4.0 (I4.0) to achieve Sustainable Development Goals [25]. The I4.0 utilizes intermixed and affiliated technologies for production and optimization [26]. Examples of I4.0 are open-sourcing information, personalized fabrication, and the Internet of Things (IoT). Open-source hardware, software, and hybrid solutions are the key ideas for I4.0, enabling users to drive innovation and optimize efficiency. The engine of achieving sustainability is innovation, which can revise the difficulty we face and convert it into an opportunity. Therefore, exploring how I4.0 can apply to CE and extending further goals to meet SDGs is vital. The researchers concluded that combining CE and I4.0 shows the possibility of developing sustainable practices in the real-world educational context and solutions for achieving the SDGs [25].

Precious Plastic is an open hardware plastic recycling project and open-source digital commons project. Dave Hakkens initiated Precious Plastic as part of his studies at the Design Academy in Eindhoven, The Netherlands [27]. In January 2020, the community expanded to the Precious Plastic Universe (PPU) as the global alternative recycling system. PPU allows people to join and explore the vision for a world with less plastic waste. This study utilizes open-source data and shared knowledge on the PPU platform to expedite the investigation process. Finally, the gathered data are utilized in a student-let design research project as a novel approach to sustainability education, where students are not just participants but co-researchers contributing to new knowledge creation.

2.3. Design Education and Sustainability Literacy

While traditional design education focuses on producing practitioners to serve the various design specializations, the current complex challenges in the industry expect designers to play significant roles in decision-making and managing the business beyond the design studio [28]. Implementing sustainability in design pedagogy seems a must-list for higher institutions since design is critical in reducing negative social and environmental impacts [29]. Furthermore, sustainable literacy is significant in design education for the above reasons [30]. Meyer and Norman argued that only a few schools cover global challenges, addressing the world’s prominent societal issues [28]. Hence, this research sought a novel approach to changing consumer behavior by linking design education directly with consumer responsibility in CE. In addition, the outcome of observing consumer behavior or waste management practices among students involved was measured as the real-world impact.

Sustainability Literacy (SL) is the knowledge, skills, and mindset that help encourage an individual to build a sustainable future [31]. While higher education is missioned to train students to elevate their SL, the training course requires multiple levels of coordination [32]. Micklethwaite also pointed out the importance of sustainable education in higher education, which is essentially transformative, constructive, and participatory, for increasing students’ SL [33].

Lewis et al. enhanced the effectiveness of hands-on learning in sustainability education for cultivating students’ engagement with the whole systematic thinking [34]. Therefore, this research intertwines I4.0 and hands-on learning with students’ design research project at the Department of Design, National Taiwan Normal University, for repurposing single-use plastic wastes to evaluate if students cultivate their SL and, furthermore, their critical thinking towards the Taiwanese sustainability issues.

3. Research Method

3.1. Participants

The study was conducted with four senior undergraduate students (three female and one male, all 22 years old) from the Department of Design at National Taiwan Normal University. Two students majored in graphic design, while the others specialized in product design. These students were selected based on their interest in combining sustainability and design in their graduation thesis project. As this project formed a crucial part of their thesis work, the participant number was intentionally small to allow for an in-depth exploration of their design process. They participated voluntarily and worked closely with the researcher throughout the study. The students were divided into two groups during the plastic waste collection phase:

• One group (Group A) was more conscious of their plastic consumption and worked actively to reduce it.
• The other group (Group B) maintained their usual consumption patterns, providing a comparative insight into plastic waste behaviors.

Since this research was conducted as part of the students’ graduation thesis projects, the participants were fully engaged in the design process and the research framework during their final academic year. This allowed for in-depth data collection and long-term observation, which are impossible in shorter studies. The structure of a thesis project provided a unique opportunity for sustained engagement with the themes of sustainability, circular economy, and plastic waste reduction.

3.2. Research Process

The project spanned from 14 November 2022 to 28 February 2023, for collecting plastic waste and until 5 June 2023, for design and research investigation. The primary goal was to examine plastic waste generation, identify potential recyclable materials, and repurpose them using open-source and additive manufacturing technologies for students’ thesis projects. The process unfolded in three key stages, collection of plastic waste, exploration of recycling methods, and design project implementation (Figure 2).

The students were each tasked with documenting and collecting their single-use plastic waste over three months. The collected plastic items were categorized based on recycled identification numbers, including PET (1), HDPE (2), PVC (3), LDPE (4), PP (5), PS (6), and Other (7). The students predominantly recorded waste generated from food packaging, such as meal containers and drink bottles, noting the type and volume of the plastic waste.

To explore recycling methods, the researcher and students utilized the PPU database, focusing on transforming the collected plastic waste into reusable materials. Polypropylene (PP) was selected as the primary material due to its abundance in waste collection—accounting for over 20% of the total volume—and its favorable properties, such as a manageable melting point of 160–166 degrees Celsius and high ductility, making it ideal for repurposing.

With PP chosen as the primary material, the group explored various ways to process it using open-source recycling machines and commercial tools like plastic shredders and heat press machines. Through this, they employed techniques such as CNC machining, vacuum forming, and laser cutting to transform recycled plastic into a design project, experimenting with different methods to achieve their creative outcomes.

3.3. Methods of Data Collection

The study utilized quantitative and qualitative data collection methods to understand the students’ engagement with plastic waste recycling comprehensively. For the quantitative data, students meticulously collected and recorded information on the types and volumes of single-use plastic waste generated over three months. The data were then organized and analyzed to determine the most prevalent types of polymers in their daily consumption, providing key insights that guided the design process.

In addition to the quantitative data, qualitative methods were employed to capture the students’ experiences throughout the project. Observations were conducted during the design process to document how students interacted with the materials and recycling tools, noting their creative approaches and problem-solving efforts. At the end of the project, interviews were conducted to gather feedback on the students’ learning experiences, the challenges they faced, and the project’s overall impact on their understanding of sustainability and environmental responsibility.

3.4. Exploratory and Participatory Action Research (PAR)

This study employs a combined exploratory and participatory action research (PAR) approach to investigate and implement sustainable design practices with senior undergraduate students. The exploratory aspect addresses the need for foundational knowledge on integrating CE principles with open-source and additive manufacturing technologies in educational settings. As a relatively uncharted area, this exploratory element provides initial insights into the students’ behaviors, attitudes, and competencies related to sustainability, setting a baseline for further analysis.

In tandem, the PAR component emphasizes active student engagement, where students are not merely subjects but co-researchers involved in a hands-on learning process. By participating directly in collecting, processing, and redesigning single-use plastic waste, students gained practical experience in CE practices. This participatory framework fosters reflective learning and iterative problem-solving, aligning with the research objective of developing SL. PAR also enabled students to actively adapt and respond to challenges as they arose, deepening their understanding through cycles of action and reflection.

Combining exploratory and PAR methodologies allowed the study to examine and influence the students’ approach to sustainable design, giving a comprehensive view of how real-world sustainability issues can be addressed within a design education framework. This dual approach informed the data collection and analysis methods, with quantitative data gathered to map plastic consumption patterns among students (exploratory) and qualitative data from observations and interviews capturing the students’ reflections, adaptive learning processes, and shifts in environmental awareness (PAR).

3.5. Interview Questions

The interview questions were designed to fully understand the students’ experiences throughout the project, focusing on design and sustainability (

Table 3. Interview questions.

No.	Interview Question
1	Could you explain your project and what is the critical factor of your design?
2	You have collected your plastic waste for a few months. What was the most significant finding?
3	Did you find any difference before and after working on this project regarding environmental awareness?
4	How do you incorporate environmental considerations into your design process?
5	What is the most significant difference between your design and recycled plastic products?
6	Was there any specific type of plastic waste you used on your project? Please also describe the reasons.
7	Please describe the difference between your project and other previous school projects, if there is any.
8	What was the most challenging part while working on your project, and how did you overcome the difficulty?
9	Did working on this project help you to develop problem-solving ability? Please also describe your reason.
10	Please share the innovative design method you have incorporated into this project.
11	After working on this project, do you have any opinion on how the circular economy can be implemented in society?
12	Please summarize your experience through this research and project.

). They covered various topics, starting with a general explanation of the project and the critical factors influencing the design. The questions explored the students’ findings from collecting plastic waste, shifts in environmental awareness before and after the project, and how they integrated environmental considerations into their design process. Additionally, the interviews delved into the differences between their project and other recycled plastic products and previous school projects. Students were asked to reflect on their use of specific types of plastic waste and the challenges they encountered, including how they overcame difficulties and developed problem-solving skills. The questions also encouraged them to share any innovative design methods incorporated into their projects and offer opinions on how the circular economy could be implemented in society. Finally, the interviews concluded by asking students to summarize their overall experience and insights gained from the research and project work.

3.6. Methods of Analysis

The collected plastic waste data were analyzed quantitatively to assess the frequency and volume of different polymer types, revealing PP as the most prevalent material and subsequently guiding the design process. The interview data were thematically analyzed for qualitative analysis to extract critical insights into students’ experiences, challenges faced during the recycling process, and their heightened awareness of sustainability issues. Additionally, observational notes were reviewed to document the students’ creative problem-solving and adaptability throughout the design process, further enhancing the depth of the analysis.

3.7. Ethical Consideration

The study was conducted according to ethical standards. All participants were informed of the research objectives and voluntarily participated. Consent was obtained before collecting personal data, and all participant information was kept confidential.

4. Result

4.1. PAR Research Results

Four senior undergraduate students (three female and one male, 22 years old) from the Department of Design at National Taiwan Normal University documented their single-use plastic waste from 14 November 2022 to 28 February 2023. The students were divided into two groups: Group A consciously aimed to reduce their plastic consumption. In contrast, Students in group B maintained their typical lifestyle without specific efforts to minimize plastic use. This PAR method allowed students to actively contribute, with the instructor guiding the project through reflection and action, emphasizing collaboration and real-world application.

The students sorted their plastic waste using recycle-identity numbers, such as 1 for PET, 2 for HDPE, 3 for PVC, 4 for LDPE, 5 for PP, 6 for PS, and 7 for other plastics. They recorded the number of items and the total volume of plastic waste. Based on the collected data, most single-use plastic waste came from food packaging, such as meal containers and drink bottles. Since most students lived in university dormitories without self-cooking facilities, they relied heavily on take-out or delivery food, contributing to the accumulation of plastic waste.

The study revealed a clear difference between the two groups: those conscious of their plastic consumption (Group A) produced significantly less waste than the others. For instance, while students in Group B consistently generated large amounts of plastic products, Group A reduced their overall waste volume, especially in high-usage plastics like PET, by making more intentional choices about plastic use. Consequently, the data showed that the total volume of plastic waste generated by the conscientious group was significantly lower, demonstrating the impact of increased awareness and intentional behavior in reducing single-use plastics. However, both groups identified PP as the most significant single-use plastic, with similar consumption volumes. Therefore, the results indicate an unavoidable need for single-use PP products for both groups of students (

Table 4. Single-use plastic waste collection sorted by the type of polymer.

	Group A: Male Product Design Student	Group A: Female Graphic Design Student	Group B: Female Graphic Design Student	Group B: Female Product Design Student
Plastic waste number by polymer type
Total Volume (g) *	800	800	2380	1750
PP Total Volume (g) *	280	280	300	380

* Collection duration was between 14 November 2022 to 28 February 2023.

).

4.2. Exploratory Research Results

After collecting single-use plastic waste, the researcher and students collaboratively investigated methods to repurpose those polymers through the PPU database, employing exploratory and PAR methods. This hands-on engagement allowed students to reflect on their experiences throughout the project, fostering iterative learning and problem-solving. The PAR approach also empowered students to participate actively in decision-making, contributing ideas for addressing recycling challenges. Since most plastic processing methods require thermal transformation, there was a specific risk of hazardous substances. Therefore, referring to data from PPU (Figure 3), the researcher and students selected PP as the primary type of polymer for their design project due to its low cyclic compounds, high ductility, colorfulness, and manageable melting point (160 to 166 °C). In addition, PP was identified as the most prevalent polymer in waste collection, constituting over 20% of the total volume, and is difficult to avoid even with conscious consumption of plastic waste. The thematic analysis of students’ reflections revealed a growing awareness of material properties, especially how these informed design decisions during recycling. Exploratory learning was particularly evident in how students navigated the trade-offs between material functionality and environmental sustainability, a core CE principle.

The PPU database exhibits a series of open-source machines that process harvested plastics from waste. Working within a participatory framework, the students actively researched how these machines could transform polymer waste through extrusion, injection, and compression. However, the complexity of these machines, which required professional mechanical engineering knowledge for assembly, led the research team to seek more accessible alternatives. The students and instructor identified a small-scale industrial plastic shredder and a commercial heat press machine with a 200 °C limit through exploratory learning. These tools allowed the students to process polymer waste into shredded particles and transform them into sheets (Figure 4). The limitations of the equipment, such as the size of the heat press bed (which capped sheet dimensions at 30 cm squares), presented challenges. The thematic observation of this phase revealed students’ creativity in overcoming equipment constraints by modularizing their designs.

To work with these thermally transformed single-use plastic marble sheets, the students and researcher engaged in exploratory experimentation using CNC machines, vacuum forming, and laser cutting techniques. They developed a flexible lighting fixture system with customizable joints, which enabled users to alter the fixture’s shape (Figure 5). The participatory nature of the research facilitated ongoing reflection on design decisions, with the students noting that they felt empowered to experiment freely with different design iterations. This resulted in diverse fixture designs, achieved by utilizing repurposed plastic sheets of varying colors and transparency. The PAR approach allowed students to present their circular system, ensuring that the final product could be reused or remanufactured rather than discarded.

4.3. Summary of Interview Responses

Based on the feedback gathered from the interviews (

Table 5. Summarized interview responses.

No.	Interview Answers
1	Our project seeks to redefine the perception of waste by transforming recycled plastic into functional and aesthetically pleasing products. By adopting traditional weaving techniques, we can shape plastic without the need for adhesives, allowing for a purer recycling process. The result is a series of lampshades with a distinctive, flowing appearance. By shredding, heat-pressing, cutting, and weaving recycled polypropylene (PP), we demonstrate that plastic waste can be reborn into valuable resources, fostering a more sustainable approach to recycling and remanufacturing.
2	Our findings showed that those with environmental awareness generated significantly less plastic waste. This difference highlighted the impact of conscious behavior and lifestyle choices on plastic usage. We also observed that the living environment plays a critical role in determining plastic consumption. For example, people living in rental spaces without a drinking fountain tended to use more plastic water bottles, while those in dormitories without refrigerators consumed more single-use packaged goods and drinks.
3	Yes, especially on the production side of material reproduction. Before the project, I followed and practiced eco-consumerism in daily life, but rarely knew about innovative technology or circular economy. Additionally, through daily waste collection, I can clearly sort the plastic waste and have a little more knowledge about plastic.
4	Since plastic has become one of the most widely used non-biodegradable materials, people often don’t take it seriously. To address this, we used plastic waste as our primary material, transforming it into items such as lighting fixtures, bowls, and keychains—objects that can be reused to enhance their value. We hope that through our project, people will gain a deeper understanding of the severity of plastic pollution and find inspiration in how we creatively transformed trash into something interesting and valuable.
5	We emphasized the experimental aspect of testing the possibilities of recycled plastic. We explored various shapes and tested how changes in temperature could reshape and deform the plastic. We applied the characteristics we discovered, such as vibrant colors and translucency, to create our final product—lighting fixtures.
6	We used No. 5 PP plastic to make hot-pressed plastic sheets. Because of the high ductility, colorfulness, and high melting point of PP plastics, subsequent products can be processed and presented better in terms of pressing, weaving, and visual effects.
7	This project took us a whole year. We had to set our goals and maintain from zero on our own. Not only should we finish our project, but we also need to hold an actual exhibition. Furthermore, this is the first time that product design students should cooperate with graphic design students. That caused some cooperation problems. However, learning how to work with different people was also an essential point in the graduation project.
8	The most challenging difficulty is the restriction of the size of the plastic sheet because of the machine, and we learned from the traditional weaving technique so that the plastic sheets can be joined without the intervention of adhesives or different materials. Different weaving methods also create a unique shape and appearance of the product.
9	Yes. We found out the problems of plastic pollution and observed our behaviors of using plastic in our daily lives. We tried to use the plastic waste we made as our materials. We were showing the possibilities of using recycled materials.
10	We tried to discover various ways of reproducing and shaping the recycled material, allowing plastic to transform into a new form. To present the diversity of recycled plastic sheets, we took pictures of the materials, even the failed ones, with different perspectives and focal lengths. Combining organic and artificial elements can create an exciting and visually appealing aesthetic.
11	It may be challenging to avoid using plastic in our lives. Then, it is necessary to develop and improve the policy for collection, sorting, and recycling. The policy may include implementing efficient waste management systems and promoting the use of recycled materials in manufacturing.
12	Throughout this research and project, we have gained valuable insights and experiences in recycling plastic materials. Our journey involved documentation, experimentation, and innovative design approaches. We tested the properties of plastics, explored various techniques for transforming recycled materials, and pushed the boundaries of what is possible.

), the research revealed that environmental awareness and conscious behavioral change played a crucial role in reducing plastic waste. Participants who actively sought to reduce their plastic consumption produced significantly less waste than their peers, illustrating how informed lifestyle choices can have a tangible impact on plastic usage. For instance, students living in dormitories or rental spaces without access to filtered water systems or refrigerators relied heavily on single-use plastics for food and drink packaging, emphasizing the role of the living environment in driving consumption. This finding underscores the challenges of maintaining a modern lifestyle without plastic yet highlights the need to raise consumer awareness to promote plastic reduction to minimize environmental impact.

The project’s collaborative challenges and problem-solving experiences also emerged as key themes. Students faced difficulties such as managing group dynamics between product and graphic design students, reflecting the complexities of working within interdisciplinary teams. Furthermore, the constraints on plastic sheet size due to machinery limitations pushed students to adapt and innovate, employing traditional weaving techniques to join smaller plastic pieces without adhesives. This experience fostered creativity and adaptability, essential in dealing with recycled materials and overcoming practical challenges.

Throughout the project, students emphasized innovative design approaches to transform plastic waste into functional and aesthetically pleasing products. Through experimentation with recycled polypropylene (PP), they employed techniques such as reshaping, heat-pressing, cutting, and weaving to create products like lampshades, lighting fixtures, bowls, and keychains. This hands-on engagement with materials allowed students to see the possibilities of repurposing waste through creative processes, thereby pushing the boundaries of what can be achieved with recycled materials.

Moreover, the project reinforced the importance of policy and the Circular Economy in addressing plastic pollution. While students acknowledged the ubiquity of plastic in modern life, they stressed the need for better waste management systems and policies that promote recycling and the use of recycled materials in manufacturing. One of the most critical insights from the interviews was that societal changes are necessary to reduce plastic waste on a larger scale, such as improving recycling infrastructure and consumer habits. By rethinking waste and embracing more sustainable practices, this project demonstrated that plastic waste can be reimagined into valuable products, providing a path toward a more sustainable future.

In conclusion, the thematic analysis revealed that this participatory project fostered deeper SL among students by encouraging hands-on learning, creative problem-solving, and collaborative teamwork. It highlighted that overcoming the challenges posed by plastic recycling requires innovation and a shift in environmental consciousness and policy frameworks. This experience has shown how design students can contribute to rethinking waste and developing circular systems to combat the growing issue of plastic pollution.

4.4. Thematic Analysis of Interview Responses

A thematic analysis was conducted on the interview responses to gain a comprehensive understanding of students’ experiences and learning outcomes. This analysis revealed several key themes that reflect the project’s impact on students’ SL, creative problem-solving abilities, and understanding of CE principles. The themes identified—environmental awareness and behavior change, creative problem-solving and design challenges, application of CE principles, impact of open-source and additive manufacturing technologies, and collaborative learning and interdisciplinary skills—provide insights into how hands-on, participatory learning experiences can deepen students’ engagement with sustainable design. Each theme highlights distinct aspects of the project, from the students’ shifts in environmental consciousness to the technical and collaborative skills developed through their work with recycled materials. The findings presented in each thematic area demonstrate the transformative potential of integrating sustainability into design education.

4.4.1. Environmental Awareness and Behavior Change

The project revealed a significant increase in students’ environmental awareness and intentional behavioral change regarding plastic use. Throughout the project, students began recognizing their daily consumption patterns and took steps to minimize single-use plastic waste. One participant noted, “I now think twice before using plastic packaging; I realize the impact of each choice”. This heightened environmental consciousness aligned with observations that students were more mindful about their plastic consumption by the project’s end, showing a direct connection between hands-on sustainability projects and increased eco-consciousness.

4.4.2. Creative Problem-Solving and Design Challenges

Students encountered various design challenges due to material limitations and equipment constraints. For instance, the limited size of available plastic sheets required them to find creative solutions to maintain their designs’ functionality and aesthetic appeal. One student highlighted, “We adapted using traditional weaving methods to join smaller plastic pieces, turning this limitation into a unique feature”. This challenge encouraged students to develop problem-solving skills and adapt creatively, illustrating the role of limitations as catalysts for innovation in sustainable design projects.

4.4.3. Application of CE Principles

The project allowed students to explore and implement fundamental CE principles, such as extending product lifecycles and minimizing waste. Through recycling and redesigning single-use plastic, students applied these principles practically, rethinking the lifecycle of their products to ensure they could be reused or repurposed. One participant reflected, “I designed my product to be reusable, aligning with CE’s goal of extending product lifecycles”. This hands-on application of CE principles fostered a deeper understanding of sustainability and responsible design.

4.4.4. Impact of Open-Source and Additive Manufacturing Technologies

Using open-source tools and additive manufacturing technologies supported students’ creative processes. Open-source resources allowed students to experiment with various design solutions and adapt using available materials. A participant commented, “Access to open-source designs allowed us to experiment freely and find what worked best for our material”. This access enabled students to innovate while working within the constraints of recycled materials, highlighting the potential of open-source tools to enhance sustainability education.

4.4.5. Collaborative Learning and Interdisciplinary Skills

Working in interdisciplinary teams fostered collaborative learning among students, teaching them valuable teamwork and communication skills. The project brought together students from different design backgrounds, which initially posed challenges but ultimately enriched their design process. “Working with graphic design students taught me to appreciate other perspectives and refine my communication skills”, shared one participant. This experience underscored the value of interdisciplinary collaboration in preparing students for real-world sustainability projects, where teamwork and diverse perspectives are essential.

4.5. Benefits of Implementing Open-Source and Additive Manufacturing Technologies

The findings in

Table 6. Observation of the benefit of implementation.

Benefits of Implementing Open-Source and Additive Manufacturing Technologies	Description
Enhanced Sustainability Literacy	Engaging students in hands-on projects using open-source and additive manufacturing technologies significantly improves their SL. This experiential learning approach deepens their understanding of the environmental impacts of single-use plastics and the importance of sustainable practices.
Creative Problem-Solving	The integration of design-based research and practical projects fosters creativity among students. They are encouraged to think innovatively about how to repurpose plastic waste, leading to the development of unique, functional products. This process highlights the potential for creative solutions in addressing environmental issues.
Consumer Behavior Insights	By involving students in the collection and analysis of plastic waste, the research offers valuable insights into consumer behavior. Understanding patterns of plastic usage and waste generation helps identify key areas where intervention can reduce plastic waste.
Practical Application of Circular Economy Principles	The project demonstrates how circular economy principles can be practically applied within an educational context. Students learn to transform waste into valuable resources, emphasizing the reduction, reuse, and recycling of materials. This hands-on experience reinforces the feasibility and benefits of circular economy strategies.
Development of Repurposing Techniques	The study explores various methods for repurposing plastic waste, including shredding, heat-pressing, and additive manufacturing. These techniques allow students to experiment with transforming waste into new products, expanding their technical skills and knowledge of sustainable manufacturing processes.
Empowerment Through Open-Source Resources	Utilizing the PPU database and other open-source resources empowers students to access a wealth of information and tools. This democratization of knowledge supports innovation and enables students to contribute meaningfully to sustainability efforts.
Promotion of Sustainable Design	Integrating sustainability into design education encourages students to consider environmental impacts in their design projects. This approach not only enhances their design skills but also instills a commitment to sustainability that they can carry into their professional careers.
Increased Awareness and Behavioral Change	The project underscores the importance of raising consumer awareness about plastic waste reduction. Students who participated in the research reported a heightened consciousness of their plastic usage and made efforts to reduce it. This behavioral change is critical for fostering a culture of sustainability.

demonstrate the unique educational and practical benefits of incorporating open-source tools and additive manufacturing technologies into students’ sustainability projects. One of the most impactful benefits was the accessibility and flexibility these technologies provided, enabling students to engage with advanced recycling processes that would otherwise be cost-prohibitive. Using open-source designs, students explored various methods to transform recycled plastic into functional products, enhancing their technical skills and adaptability. This accessibility encouraged experimentation, as students could try different iterations, expanding their capacity for creative problem-solving in sustainable design.

Additionally, using additive manufacturing technologies allowed students to directly apply CE principles in their projects. Working with recycled materials pushed students to rethink the entire lifecycle of their products, from creation to potential reuse or repurposing. This experience fostered a practical understanding of CE, illustrating how design can contribute to reducing waste and resource consumption. By engaging in the whole process, from collecting waste to designing and producing items with a purpose, students gained firsthand insights into the challenges and possibilities of CE, strengthening their SL.

Furthermore, implementing these technologies facilitated a collaborative learning environment, allowing students from diverse design backgrounds to share knowledge and approaches. This interdisciplinary collaboration enhanced their ability to work as a team and encouraged cross-disciplinary skills, such as communication and collective problem-solving. The open-source platform enabled students to access a shared ideas database, fostering a community-oriented approach to innovation and resource-sharing.

In summary, integrating open-source and additive manufacturing tools supported students in developing practical skills and creative solutions. It offered them a unique perspective on sustainable design’s role in achieving a circular economy. These tools provided an invaluable foundation for experiential learning, reinforcing the relevance of accessible, collaborative, and adaptable approaches in sustainability education.

5. Discussion

This study demonstrates the effectiveness of integrating open-source and additive manufacturing technologies within a participatory, hands-on project to enhance SL among design students. These findings align with prior research highlighting the importance of interdisciplinary education in promoting students’ SL. For instance, Santiani (2024) emphasized that interdisciplinary learning approaches can improve environmental literacy, equipping students with the necessary skills to engage in sustainable behaviors [36]. In our project, students actively engaged with plastic waste recycling, increasing their understanding of the environmental impact of design and material choices. This supports Kokkarinen and Cotgrave’s (2013) findings that students often demonstrate SL through active participation in hands-on activities, even when traditional classroom settings limit transformative experiences [37].

The students’ learning experiences, as documented in their graduation thesis project outcomes and qualitative interview feedback, revealed critical insights. Students became intensely aware of the plastic waste problem in their everyday lives, specifically the widespread use of single-use plastics and the difficulties involved in disposal and recycling. The theme of SL development emerged strongly as students engaged with the complexities of plastic waste management, acquiring substantial knowledge of Taiwan’s recycling system. By the project’s end, their understanding of plastic materials, lifecycle impacts, and recycling processes had increased significantly.

Problem-solving challenges were another critical theme identified in the study. Students encountered multiple hurdles, including considering the entire design lifecycle and overcoming equipment limitations when producing recycled plastic products. Park et al. (2022) emphasized that design education incorporating sustainability principles can foster critical thinking and encourage students to address pressing environmental issues creatively [38], which aligns with our study’s goals and findings. Students devised unique solutions by working within material constraints, such as using weaving techniques to join plastic pieces. This process reflects broader educational trends such as STEAM and STEM4S, emphasizing creative and interdisciplinary learning as vital to addressing real-world problems (Figure 6).

The findings from this study underscore the limitations of the traditional education model [39] in addressing complex, interdisciplinary challenges such as plastic waste management and circular economy (CE) implementation. Traditional education often focuses on discipline-specific learning with rigid subject boundaries, limiting students’ ability to tackle real-world problems that require an integrated, holistic approach. This approach is typically theoretical, placing less emphasis on hands-on, practical learning and creativity, which are essential for addressing environmental and sustainability issues.

In contrast, the STEM model encourages students to engage in problem-based learning that integrates knowledge from various disciplines. While STEM emphasizes technical and scientific skills, it often lacks an explicit focus on design thinking and creativity, which are crucial when addressing issues like plastic waste. STEAM goes further by incorporating the arts and design into the STEM framework [40], promoting a more creative approach to problem-solving. This allows students to explore aesthetic and innovative solutions, as seen in this project, where students experimented with design techniques like weaving and additive manufacturing to transform plastic waste into functional products.

The STEM for Sustainability (STEM4S) framework expands upon these models by explicitly integrating sustainability as a central goal of education [41]. This model goes beyond the technical and creative aspects of STEM and STEAM by ensuring that environmental impact and sustainability are always part of the problem-solving process (Figure 6). In this research project, students worked within the STEM4S framework to experiment with materials and design and consider the environmental lifecycle of their products. Their ability to create aesthetically pleasing, functional products from recycled plastic exemplifies the strengths of STEM4S in fostering SL and creative problem-solving.

Open-source resources enabled students to explore the potential of additive manufacturing and circular design. Students could experiment with new materials and techniques by utilizing open-source plastic shredding and heat-pressing machinery, fostering innovation and enhancing problem-solving capabilities. This approach allowed for a deeper engagement with CE principles as students explored how plastic waste could be transformed into aesthetically pleasing, functional products, such as lighting fixtures and household items. This reflects findings by Ravindran (2020), who discussed how open-source and DIY technologies democratize access to innovation, allowing researchers to experiment with limited resources [42].

The exploratory nature of the research, combined with the PAR approach, was particularly effective in uncovering the real-world challenges of implementing CE principles. Students grappled with the practicalities of working with recycled materials, which required constant reflection and adaptation. The thematic analysis of interview feedback highlighted that while students could experiment with sustainable design practices, they also encountered behavioral and structural limitations related to recycling processes and consumer habits. For example, students noted how consumer behavior—influenced by living environments and convenience—significantly impacted plastic waste generation. This understanding allowed them to see how small-scale innovations could be scaled up to influence broader societal and environmental change.

Ultimately, this research project shows how design education can contribute to CE by fostering SL and encouraging students to engage in environmental problem-solving through the thesis project’s long-term, immersive nature. The students’ success in transforming waste into usable products demonstrates the potential of hands-on learning and open-source technologies to foster sustainable innovation. Furthermore, the findings provide a framework for integrating CE principles into educational curricula, showcasing how interdisciplinary approaches and the STEM4S framework can achieve a circular society.

Figure 6. Comparison of educational models diagrams: (a) 20th century single-disciplinary educational model; (b) STEM interdisciplinary educational model adopted from Sen, Ay, and Kıray [43] (re-illustrated by author); (c) STEM4S multi-disciplinary educational model based on the STEM interdisciplinary educational model.

Figure 6. Comparison of educational models diagrams: (a) 20th century single-disciplinary educational model; (b) STEM interdisciplinary educational model adopted from Sen, Ay, and Kıray [43] (re-illustrated by author); (c) STEM4S multi-disciplinary educational model based on the STEM interdisciplinary educational model.

6. Conclusions

This study explores the critical role of education in promoting the circular economy CE and reducing single-use plastic waste in Taiwan through integrating open-source technologies, additive manufacturing, and participatory action research (PAR) methods. The research revealed the benefits of exploratory methods in addressing complex sustainability challenges by engaging design students from the National Taiwan Normal University in a hands-on, project-based learning experience for their graduation thesis project. The combination of empirical research and PAR allowed students to actively contribute to both the design process and the sustainability outcomes, fostering a deeper connection to the environmental impact of their design work.

The thematic analysis of student interviews and project outcomes highlighted several key findings. First, students experienced a notable increase in environmental awareness, understanding how their behavioral choices influence plastic waste generation. Second, the study uncovered significant challenges in working with recycled plastic, such as equipment limitations and the need to account for the entire design lifecycle. These challenges, however, were mitigated by the creative use of adaptive manufacturing tools like laser cutting and vacuum forming, showcasing how interdisciplinary approaches can generate innovative solutions in sustainable design.

This research used exploratory methods to demonstrate the importance of trial and error, experimentation, and reflective practice in design education. The PAR method was particularly effective in immersing students in the problem-solving process, allowing them to identify real-world problems and actively participate in generating solutions. Furthermore, thematic analysis provided critical insights into students’ experiences, helping to identify patterns of behavioral change, increased SL, and collaborative problem-solving.

Ultimately, this research suggests that integrating sustainability education into design pedagogy—using hands-on learning and multidisciplinary approaches—can equip future designers with the tools and mindset to tackle circular economy challenges. The success of CE depends not only on technological innovations but also on societal participation and a collective commitment to sustainability principles. Therefore, education plays a pivotal role in shaping a sustainable future, with this study serving as a model for how design education can foster creativity, innovation, and environmental responsibility.

In conclusion, the findings from this research offer a framework for future investigations into other types of waste reduction and educational models that promote sustainable design. By integrating exploratory research, PAR, and thematic analysis, this project demonstrates the potential to revolutionize design education, placing sustainability at the core of future design practices across industries. This study serves as a foundation for ongoing research in sustainability education, potentially influencing national and global policies on plastic waste management and circular economy implementation.