Keywords

1 Introduction

The development of Smart Cities is based on the intensive use of technology and urban planning. This process allows for the design of new solutions, by promoting the conscious use of resources, and preserving them for future generations.

In this context, electronic waste disposal is a challenge to be investigated. Technological devices are frequently disposed of in common waste bins. These items contain several substances that may cause serious damage to the environment and human health and, at the same time, have economic value.

The Mobile and IoT (Internet of Things) technologies can, for instance, provide alternatives by informing citizens of the importance of electronic waste disposal, the location of collection points, and characteristics and status of recycling bins. In addition, they can support waste disposal management and planning. However, it is still necessary to improve the design methods and solutions for systems that integrate mobile applications and IoT in the context of sustainable smart cities.

In this paper, we propose a design method focused on the effective participation of citizens and experts during the entire design process of mobile and IoT solutions to electronic waste disposal in sustainable smart cities. This method is based on principles and techniques of Participatory Design (PD) [1], hackathon events for smart cities [2], and Personas [3].

According to Vácha et al. [4], citizens will be more willing to accept a smart city solution if they participate in its design. Participation can also increase citizens’ initiative, leading them to carry out activities to support sustainability and improve quality of life in the city. Alba et al. [2] emphasizes that thematic hackathons on the theme of smart cities have increased as governments, universities, and corporations have been engaging in the subject.

Personas are fictional characters, which represent users, and include their characteristics, goals, and behaviors. In our method, Personas are used to stimulate the participatory process, and to express citizens’ characteristics and needs in the hackathons’ descriptions.

We propose the Participatory Hackathon Method for Sustainable Smart Cities (PHMSSC). This method is composed of five main phases that are executed iteratively, as follows: (1) Problem Definition and Design of Personas, (2) Hackathon Design, (3) Hackathon Application, (4) Design of the Final Candidate Solution, and (5) Prototype Development.

The PHMSSC was evaluated through the design of a mobile application, integrated with IoT devices of smart recycling bins, in the context of Brazilian cities. First, an initial description of the problem was produced to delineate the system’s scope.

Subsequently, an expert (first author) designed Personas. He created an initial version of the Personas, based on demographic information from big cities in Brazil. These Personas were complemented by other experts, and validated and improved by students and local citizens using feedback from forms on the Web. The Personas were then revised and included in the Hackathons’ descriptions. We created four Personas, two males and two females. All of them have information about the importance of recycling electronic waste, but they have experienced difficulties with the electronic waste disposal of different devices.

Four Hackathon sessions were performed. The participants are technical level (high school) students in Computing, Electronics, Logistics, and Work Safety from Centro Paula Souza, in São Paulo State, in Brazil, as well as invited citizens from the city of São Paulo.

A system prototype was constructed from the results of the Hackathons, and focus group sessions with citizens and experts. Characteristics of this prototype are presented and discussed in this paper. The solution includes a mobile application with georeferenced information to support users in the process of finding the nearest disposal bin, as well as the use of IoT devices that provide information on the status of these bins, as well as management information for the city hall and citizens.

Therefore, the main expected contributions of this paper include: (1) a better understanding of the design process of Sustainable Smart Cities solutions, (2) the proposal of an innovative participatory method based on Hackathons and Personas, and (3) a prototype and empirical results regarding the execution of this method in an application design scenario.

The remainder of this paper is organized as follows: Sect. 2 presents background information. Section 3 details the PHMSSC method. Section 4 presents the case study and reports on the obtained results. Section 5 concludes the paper and suggests future work.

2 Background

This section presents the definitions of key concepts and background information on related fields, including sustainable smart cities (Subsect. 2.1), IoT (Subsect. 2.2), PD (Subsect. 2.3), Personas (Subsect. 2.4), and Hackathon and Design Thinking (Subsect. 2.5).

2.1 Sustainable Smart Cities

Smart cities can be understood as the use of technology to enable the communication, mediation, and integration of information systems, infrastructure, among others [5]. This results in innovative environments, conducing to the balanced development of technological solutions for cities’ problems. The components of a smart city include smarts [6]: transportation, health, security, education, energy, environment, among others smart policy domains.

A sustainable city can be defined as an urban space, which aims to meet the physical, cultural, social, environmental, economic, and political needs and aspirations of the population. Resources should be used in an efficient way in order to achieve this objective.

Sustainable smart cities use information and communication technologies, and other technological resources, to improve quality of life, the efficiency of urban services and operations, as well as increase competitiveness. They arise to meet present and future generation’s needs, including social, economic, cultural, and environmental aspects. In a sustainable smart city, citizens’ needs are met without compromising the needs of other people and future generations [7]. These objectives must be considered in the design of information technology based solutions for sustainable smart cities.

In the Brazilian context, a law [8] provides for the shared responsibility of waste generators. Manufacturers, distributors, importers, merchants, public services providers, and citizens share the responsibility of addressing the issue of waste from electronic devices.

2.2 IoT and Sustainable Smart Cities

A large increase in the number of IoT connected devices is expected over the next few years [9]. Nowadays, the IoT is developing in various domains, for instance, smart grid and transportation. Novel IoT solutions are also present in the context of sustainable smart cities, particularly in waste management, including solutions such as smart trash bins [10]. For instance, Dublin has smart trash bins using solar energy and wifi connections. A smart trash bin can, for example, inform public services that it needs to be emptied or needs maintenance, as well as automatically compacts waste (improving their capacity).

There are various possibilities for using IoT by integrating it with mobile applications. Smart trash bins can support citizens by informing their characteristics and current status to users nearby, guiding users to go to the correct place and dispose of waste properly.

At the same time that there are innovative IoT solutions, new challenges must be faced. Such challenges are related to the various aspects that must be considered during the design process. These aspects range from technical ones (e.g., calibration of sensors) to the social ones (e.g., usage habits and privacy).

2.3 Participatory Design and Smart Cities

PD [1] has its roots in the democratization of design practices in industry during 60’s in Scandinavia. PD can be used to provide a broader and more accurate view of requirements, as well as elicitation of design alternatives, through effective user participation during all phases of the design process.

PD can also boost the innovation process [4] of solutions for smart cities. Such solutions are developed with the participation of the stakeholders, who can, for instance, express and clarify their needs, and propose, improve, and evaluate solutions. Citizen participation during the design process allows for the incorporation of different perspectives in Smart City projects.

One expected benefit of the use of PD in Smart City projects is the improvement of the user acceptance rates. Users tend to be more flexible and open to changes when they participate of the design process [4]. Participation in these projects can increase the citizens’ initiative towards sustainability, and quality of life in the city. Users can develop a more systemic view of the projects by sharing their needs and preferences with each other, by creating solutions based on real evidences, and by increasing their sense of responsibility.

In this paper, PD principles and techniques are used in conjunction with Personas to stimulate and facilitate the design-participants’ communication. Hackathon and DT activities presuppose the stakeholders’ participation, and are complemented by participatory sessions. The next sections present Personas, Hackathon, and DT respectively.

2.4 Personas and Smart Cities

The Personas technique makes use of fictional characters during the design process [3]. These fictional characters are designed by means of analysis and a combination of users’ profiles [11]. They reproduce their desires, needs, motivations, and expectations; thus, represent key characteristics of a group.

The design of Personas [3] is based on the analysis of demographics and bibliographic data, as well as creativity, aiming to create a character nearest to the reality of the users at the time that the application is designed.

Empathy maps [12] can support the design of the Personas, since we can consider how the users’ think, feel, see, hear, say, and do things. Considering the context of the design of sustainable smart cities, it is necessary to describe how the Personas are committed to environmental aspects and sustainability of the city.

2.5 Hackathon, Design Thinking and Smart Cities

Hackathons are events with participants who have various profiles (e.g., designers, programmers, engineers) working collaboratively on a specific theme/problem over a period of time [2, 13]. Frequently, hackathons have small groups (although there are cases with large groups) working intensively during a short period of time.

Hackathons, in the context of smart cities, are relatively new. In 2008, a pioneer smart city hackathon in Washington DC occurred, named “Apps for Democracy”. This event was followed by a series of events to promote innovative solutions for the city, engagement of its citizens, and mapping of the citizen’s real needs. In the last decade, organizations, such as the “Code for America” [14], have been promoting smart city hackathons.

According to [2], the number of hackathons linked to smart city themes increased as governments, universities, and corporations became engaged in the issue. Global Urban Datafest [15], CityOS Hackathon [16] and Barcelona Smart City App Hack [17] are examples of events with hackathons focused on themes related to smart cities and innovation.

DT is used to structure the activities and promote good design practices during hackathons. DT aims to solve design problems in a collaborative way, with the stakeholders at the center of the design process. DT can support innovation in information technology, increasing the perceived value of the solution by affecting peoples’ lives [18]. DT can benefit the hackathon by structuring insight generation and improving proposals [19] in an interactive way. DT can be used with hackathons [20] to improve public services in an iterative innovation process as well.

3 The Participatory Hackathon Method for Sustainable Smart Cities (PHMSSC)

As shown in Fig. 1, the PHMSSC has 5 phases, detailed in the following paragraphs.

Fig. 1.
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Overview of the PHMSSC

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Phase 1: Problem Definition and Design of Personas.

This phase contains three steps that aim to describe the problem and to design Personas that represent the citizens’ characteristics and needs.

  • Step 1.1 – Problem definition: Designers and stakeholders work together, aiming to clarify the problem in focus. Well-structured methods or even unstructured meetings can be used according to the complexity of the problem. A well-defined problem description is imperative for the next steps of the design.

  • Step 1.2 – Design of personas: Starting from the definition of the problem, designers should consider demographic aspects to base their design of an initial version of the Personas. Qualitative aspects related to the users’ behavior should also be considered.

  • Step 1.3 – Validation of personas: Quantitative and qualitative analysis is performed using face-to-face workshops and online resources (to achieve a wider audience). Web forms should be carefully designed, and the audience well defined. The audience should include citizens and experts. Meetings with experts and users are necessary to evaluate the collected data and discuss their impacts on the design of the Personas. If necessary, the three steps in this phase can be repeated until a satisfactory evaluation of the Personas is achieved.

Phase 2: Hackathon Design.

Experts and citizens work together to design the hackathon events according to the following steps:

  • Step 2.1 – Choose a hackathon platform. The designers, in the role of hackathon administrators, should select and setup a hackathon platform according to the problem and objectives.

  • Step 2.2 – Create a new hackathon. The hackathon administrators should create a new hackathon in the platform, give it a name, and define a time period for its completion according to the problem and project’ objectives.

  • Step 2.3 – Select the participants. The hackathon’s administrators should select the team members, mentors, and judges. They should invite members with various profiles (e.g., designers, developers, managers), and citizens according to the scope and objectives of the project. It is important that citizens participate in the role of judges as well.

  • Step 2.4 – Create/prepare training resources. By using online platforms, hackathon administrators should create or prepare necessary training resources to be made available prior to the hackathon sessions. These resources include concepts specifically related to the hackathon (e.g., platform tutorial, tools, methodologies, DT concepts), personas, PD, as well as concepts related to the project domain (e.g., electronic waste disposal, IoT technology, Mobile technology).

  • Step 2.5 – Prepare for execution. Hackathon administrators should create or prepare the content (text, image, presentations, video) to be presented during the hackathon. This content includes, for instance, a review of the hackathon’s concepts, a summary of the problem’s definition, a definition of related concepts, and descriptions of previous projects (if any). In this step, the administrators create the teams, attributing responsibilities and roles according to the step 2.3.

  • Step 2.6 – Mentorship requests. The team members may request external mentoring through the hackathon tool, which can be provided by other participants of the project.

Phase 3 - Hackathon Execution.

This phase is the hackathon’s execution itself, as planned during the last phase. This phase includes four steps as follows:

  • Step 3.1 – Opening presentations. Hackathon administrators (and mentors) present the initial content, as produced during the step 2.5.

  • Step 3.2 – Present the Personas to the hackathon teams. The administrators present the Personas to the teams. The teams will collaboratively propose solutions with the support of these personas.

  • Step 3.3 – Execute the hackathons. The hackathon team proposes design solutions according to the Personas and problem descriptions.

  • Step 3.4 – Hackathon’s evaluation. Judges evaluate the teams’ design proposals. Aspects related to citizens’ needs, innovation, environmental requirements, viability of the project, business, and technical aspects should be balanced in the project evaluation. Democratic principles (from PD) should also be observed.

Phase 4 - Design of the Final Candidate Solution.

This phase has the objective of answering the following question: “How to consider the results of the hackathon in the design of a final candidate solution?”. This phase has two steps:

  • Step 4.1 – Analysis of the projects. Designers and guest citizens verify the evaluation scores and the judges’ comments (step 3.4). A designer makes an initial report based on the judges’ comments and score, emphasizing the strengths and drawbacks of each project. This repost is evaluated in a meeting with other designers and citizens. The best design alternatives are selected to be used as input for the next step.

  • Step 4.2 – Adapt solutions. The designers (with citizen participation) adapt, complement, and merge the best alternatives presented during the hackathon. For instance, a team could propose a good design for a smart recycling bin, but with bad sensors and energy solutions, while another team (with a lower overall score) could propose a good solution for sensors and energy use. Those solutions can be integrated in this step.

Phase 5 – Prototype Development.

In this phase, there is the iterative development of functional prototypes.

  • Step 5.1 – Iterative development. This step is the iterative development of functional prototypes, including redesign, implementation, and testing of solutions. This step must be adapted according to the development process and technologies required by the design solution. For instance, the complexity of the adopted IoT technology must be considered. Citizens should also participate of this step. Usability evaluations can be carried out.

  • Step 5.2 – Field evaluation. After prototyping cycles, the final version of the solutions should be analyzed in field studies. The empirical feedback can be used in the development of the next versions of the solution.

4 Case Study

This section presents a case study conducted with the objective of evaluating and improving the PHMSSC, and analyzing solutions for collecting electronic waste using smart recycling bins and mobile technology. Subsection 4.1 presents the context, participants, and tools. Subsection 4.2 describes the preliminary results including the design alternatives (from the hackathon), and the evaluation of these alternatives to base the construction of a functional prototype.

4.1 Context, Participants and Tools

The case study took place in São Paulo City, Brazil, during October 2018. The hackathon activities occurred during the “034 Jornada Hacker - Etec Prof. Aprígio Gonzaga”, Centro Paula Souza, in São Paulo State – Brazil. The other activities in the case study also used Centro Paula Souza’s infrastructure.

The participants were invited in person, including professionals, students (classroom invitations), and citizens. Considering the phases, the participants of this case study include:

  • Twenty (20) Students from Centro Paula Souza, in São Paulo State – Brazil. The students were divided in four groups. Each group is composed of one Informatics/Software Development student, two Electronics students, one Logistics student, and one Work Safety student. The students participated in phases 1 to 3.

  • Three (3) Professional Developers: two hardware and one software expert. The developers participated in phases 2 to 5.

  • Eight (8) hackathon judges, co-designers, and evaluators: These participants represent citizens with an interest in the solution. They are teachers and public servants in the role of citizens interested in sustainable smart cities. They participated in phases 3 to 5.

  • A hackathon mentor, with experience in mentoring innovation oriented hackathons.

The Google FormsFootnote 1 platform was used in phase 1 to register both online and face-to-face activities. We used the ShaweeFootnote 2 platform to manage our hackathon activities. The students participated in an online training (as proposed by PHMSSC) before the hackathon, which included the following topics: active methodologies, DT, empathy maps, and canvas. Four teams were created in the Shawee platform, and internal roles (UX designer, developer, businessman) were attributed according to their profiles and interests.

The description of the hackathon included the Personas, as well as a prototype of the mobile application named LCLE (Localizador Coletor de Lixo Eletrônico) [21]. This application was used as a starting point for the activities. The LCLE informs users of the current location of nearby recycling bins.

4.2 Preliminary Results

This subsection presents results of the case study, considering the application of the PHMSSC method in the context presented in the last subsection.

Modeled Personas

As a key result of the first PHMSSC phase, there are four modeled Personas (two male and two female). We considered demographic information, the problem’s definition, as well as qualitative aspects discussed in meetings with the participants in the design of the Personas. The focus was to design personas that experienced situations and have concerns regarding electronic waste disposal. Subsequently, the Personas were validated with students and citizens using online forms. Key Personas’ characteristics can be briefly summarized as follows:

  • Persona 1 – Vitória. She is 28 years old; she is single, and is an undergraduate student of Architecture and Urbanism courses. She is doing an internship in an architecture office. As most Brazilians, she has a smartphone with internet access and uses it to access social networks. Recently, the office where she is interning exchanged its computers. She had serious concerns regarding this change, since they had not found an appropriate alternative for disposing of the electronic products. She tried to share her concerns in the office. Vitória believes that it is possible to improve the efficiency of urban operations and services, as well as to improve sustainability by considering architecture and technology together.

  • Persona 2 – Melissa. She is 34 years old; she is married, and is a project manager at a telecommunication company. As most Brazilians, she has a smartphone with internet access and uses it to access social networks. Melissa has serious concerns about the future of her children. The organization she works in generates huge amounts of electronic waste, such as computer components, telecom devices, smartphones, and batteries. She would like to develop a culture of recycling electronic waste in her department. She believes it is possible to make cities more sustainable by using technology, since this allows for the use of resources in an efficient and balanced way.

  • Persona 3 – Marcos. He is 29 years old; he is single, and is a trainee in a law office. He has a smartphone with internet access and use it to watch videos, to listen to music, to make banking transactions and, less frequently, to access social networks. Recently, the law office where he is working discarded two computers in a common trash bin. Marcos believes that a better destination could be given to this electronic waste, but advances in the city’s administration are needed. He emphasizes that information technology is a key aspect to improve the efficiency of urban operations and services, as well as competitiveness.

  • Persona 4 – Lucas. He is 30 years old; he is married, and is a military officer. He is patriotic and understands the importance of sustainability for future generations. He is responsible for the informatics office of a military base. There is a storehouse on the base, where electronic waste was stored for years. However, it is almost full, and he understands that this electronic waste can cause damage to nature. He is looking for a sustainable alternative to dispose of part of the electronic waste.

The Personas were analyzed by students from Centro Paula Souza, in São Paulo State – Brazil during October 2018. Twenty-three (23) students answered the evaluation form of the Persona Vitória, 32 Melissa, 27 Marcos, and 13 Lucas. Table 1 presents results of this analysis of the problem posed by each Persona described above. The researchers analyzed the qualitative responses, and ranked three questions to represent typical responses. These responses were included in this paper. Table 1 presents results of three of the representative responses for two qualitative questions and two quantitative questions:

Table 1. Examples of responses and quantitative results of the Personas’ evaluation questions
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  • Question 1: What are the actions that Persona XX can take to solve his/her problem?

  • Question 2: Have you faced a situation similar to the described by Persona XX? () Yes or () No.

  • Question 3: If yes, describe this situation.

  • Question 4: Do you think Information Technology can be used to solve this problem/situation? () Yes or () No (Table 1).

Hackathon Results

The four groups used different approaches, focusing in one Persona each. They described their prototype and ideas as follows:

  • Group 1 – Persona Vitória. We prototyped a standard recycling bin with an integrated display. This display shows the items that should be discarded in the respective bin. This recycling bin also helps the users evaluate if the waste should be discarded. The group also proposed that the recycling bin could include sensors to identify electronic object (before opening it). The recycling bins are integrated with a mobile App to inform their locations, characteristics, and status.

  • Group 2 – Persona Melissa – We will use App Inventor to include the IoT Technology into the LCLE. We projected a prototype using NodeMCU, which integrates weight sensors, gas sensors, ultrasonic sensors, and some motors that will give better function and safety to the project. The ultrasonic sensors are used to automatically open the recycle bins. These sensors will inform a transportation system, which will pick up the material to be discarded when it is full, reorganizing the process, and avoiding waste of time. We also propose a safety protocol, where experts evaluate the risks in the transportation and recycling process, according to the sensors’ data.

  • Group 3 – Persona Marcos – To solve this problem, we created an app that informs citizens of where to dispose of electronic waste. This app is integrated with the system in a company that collects, processes, and forwards waste to other companies specialized in electronic waste recycling. This waste should be disposed in waste bins with sensors that will identify when it is full, and automatically inform the company.

  • Group 4 – Persona Lucas – The organization that produces the electronic waste can use the LCLE application to inform the type/content of the waste. This organization could search a container nearby (using geolocation) and contract another company, which is responsible for recycling electronic waste. There are volume and weight sensors to notify the status of the container for both the organization that produces the electronic waste, and the company responsible for recycling electronic waste.

Judges Scores and Comments

The judges (cf., Subsect. 4.1) attributed scores to each hackathon group according to their proposals and prototypes. In addition, they provided text comments. Table 2 presents the final score for each group as well as three comments selected by the researchers to represent typical responses.

Table 2. Judge’s score and comments for the Hackathon prototypes
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Design and First Prototype

The researchers and judges listed the design alternatives presented by the groups and selected those that were considered the most interesting. For instance, Group 1 uniquely presented a display in front of the recycling bin, Group 2 proposed the use of ultrasonic sensors, Group 3 used sensors to identify when the recycling bin is full, and Group 4 proposed the use of volume and weight sensors. Using this analysis, a design proposal was elaborated with the following characteristics:

  • The prototype makes use ultrasonic sensors for the automatic opening of the bin. The user can move their hand near the recycling bin to automatically open it.

  • The researchers considered that alternative proposed by group 3 was the best one to identify when the trash is full. This is due to the resources available to implement the prototype. Thus, lasers were inserted internally to identify when the recycling bin is full.

  • The prototype also used a display to inform the type of electronic waste disposable in a specific recycling bin.

Figure 2 presents a prototype, considered the first prototyping cycle of Step 5.1 of the PHMSSC method. Thus, this case study is comprised of the five phases of the PHMSSC. It is important to note that the execution of the method resulted in a set of valuable design alternatives, which is a result of the interaction between participants of the hackathons, judges (citizens), and designers.

Fig. 2.
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Recycling bin prototype

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5 Conclusion and Future Work

Electronic waste disposal is one of the key challenges in the development of sustainable smart cities. In this paper, we presented the PHMSSC method, and a case study involving several students, citizens (in the role of hackathon judges and co-designers), and experts. Four groups proposed a set of design alternatives, which make use of mobile applications and IoT technologies to provide solutions for smart recycling bins. The Personas technique acted as an important resource to support a better understanding of the problems and communication with the students (88.8% of the students considered that Personas improved their understanding of the problem). In addition, citizens (as judges) had a broader view of all the projects, which made is possible for them to select the best alternatives (from the groups) to implement in a prototype.

As the next steps of this research, we propose the evaluation of a prototype, including field studies in Centro Paula Souza’s campus.