Sketching in Circuits: Designing and building electronics on paper Jie Qi Leah Buechley MIT Media Lab MIT Media Lab 75 Amherst St, E14 548 75 Amherst St, E14 548 Cambridge, MA 02142 Cambridge, MA 02142 [email protected] [email protected] ABSTRACT protoboard, and the printed circuit board (PCB). The field of new methods and techniques for building electronics is quickly growing—from research in new The breadboard provides a press-fit grid for quick materials for circuit building, to modular toolkits, and more connections and disconnections for testing circuits and recently to untoolkits, which aim to incorporate more off- modification. Since these circuits are built using only the-shelf parts. However, the standard mediums for circuit press-fit connections, breadboards are great for fast design and construction remain the breadboard, protoboard, prototyping but quite fragile as final products. Protoboards and printed circuit board (PCB). As an alternative, we are a more permanent solution in which components are introduce a method in which circuits are hand-made on soldered down to a board that is precut with a grid of holes. ordinary paper substrates, connected with conductive foil The PCB is the most permanent solution, in which tape and off-the-shelf circuit components with the aim of components are soldered onto a pre-designed circuit board. supporting the durability, scalability, and accessibility Unlike breadboards and protoboards, PCBs also give users needs of novice and expert circuit builders alike. We also the freedom to arrange components spatially on the board used electrified notebooks to investigate how the circuit with the help of CAD software. Their digital nature also design and build process would be affected by the allows PCB designs to be easily checked by CAD, shared constraints and affordances of the bound book. Our ideas and replicated. However, the PCB design process requires and techniques were evaluated through a series of users to wait for the board to be fabricated—which can take workshops, through which we found our methods supported a few hours to a few days—before designs can be tested. a wide variety of approaches and results—both technical Once produced, PCBs are difficult to modify, making this and expressive— to electronics design and construction. process ideal for amplification but slow and inconvenient for prototyping purposes. Author Keywords An interesting alternative approach to prototyping and Paper computing; toolkits; sketchbooks; circuit prototyping. building circuits is ugly construction, in which circuit components are soldered directly to each other in mid-air ACM Classification Keywords over a rigid ground board [22]. This method allows J.5 Arts and Humanities creators to spatially arrange their components, create permanent circuits, and test their creations immediately. INTRODUCTION However, the circuit connections are often unclear because More and more communities are becoming interested in these three-dimensional circuits are difficult to plan and creating their own hardware, as the tools of design and tend to be constructed organically. In addition, the exposed application space of electronics become more diverse and component leads make short circuits very common. accessible. Despite advances in the technology itself, the In this paper, we introduce an alternative method in which standard mediums people use to design and build circuits are hand-made on paper substrates with conductive electronics remains largely the same: the breadboard, the foil tape and off-the-shelf circuit components. This process incorporates the tinkerability and immediate feedback of Paste the appropriate copyright/license statement here. ACM now breadboards, protoboards and ugly construction. It also • ACM copyright: ACM holds the copyright on the work. This is the allows users to visually and spatially lay out their circuit as historical approach. with PCBs. Paper as a circuit substrate also affords all the • License: The author(s) retain copyright, but ACM receives an exclusive publication license. qualities of any other paper-based craft. For example, users • Open Access: The author(s) wish to pay for the work to be open can sketch and annotate, cut and fold, digitally scan, or access. The additional fee must be paid to ACM. even bind their circuits into books for archival. In addition This text field is large enough to hold the appropriate release statement to exploring the techniques on paper, we also investigate assuming it is single-spaced in TimesNewRoman 8 point font. Please do how building circuits in book form through electrified not change or modify the size of this text box. sketchbooks—recalling the process of traditional sketching—affects the circuit design process and resulting researching methods for preserving the physical book form artifacts. while augmenting them with electronic qualities. In addition to [17], many have integrated digital features to the RELATED WORK This work builds upon a body of research most notably traditional book format, allowing users to remotely centered around the concept of untoolkits [13], materials communicate through book interfaces [5], interact with approaches to building circuits on paper, and electronically sound while reading a story [1], and connect a physical book to a web interface [21]. Others have looked augmented books. specifically at how digital features can help note-taking through augmented notebooks [10] and [11]. Workshops Untoolkits Given the growing research in non-traditional approaches to [18] and [6] have also emerged to both preserve and guide building electronics, many researchers are now looking at the evolution of physical books in this increasingly incorporating more off-the-shelf and existing components electronic and digital age. In our work, we are similarly and materials, the untoolkit approach, to make these inspired to analyze the affordances of the physical book, techniques more accessible and reach more diverse especially in the note-taking and design aspect, and transfer audiences. From a craft perspective, squishy circuits [9] is a this to the process of circuit building. circuitry sculpting technique using conductive modeling clay and Perner-Wilson [15] systematically studied a METHOD FOR MAKING PAPER CIRCUITS variety of traditional craft practices, to see how existing The following process summarizes a flexible and hand- materials and techniques could be applied to circuit made approach to building circuits on paper using off-the- building. Mellis et. al. [13] used off-the-shelf shelf electronic components and common household microcontrollers, traditional craft materials, conductive ink supplies (Figure 1). and open hardware and software tools to create an approach to circuit building that is friendly to new circuit builders by relying on familiar craft techniques. In Invent-Abling [8], soft circuit kits were designed to be as simple and bare as possible, to encourage users to incorporate other local materials. Finally, the MakeyMakey kit [12] is a board that specifically requires users to find common materials to complete the circuit-building activity. Inspired by these approaches, we designed our method to incorporate materials that are familiar and easy to use and off-the shelf for accessibility. Building circuits on paper There have also been many explorations of how to incorporate circuits with paper from a materials perspective. Some approach this challenge through materials science investigations on new conductive inks for drawn [18], printed [10] and painted [2] circuits. Others, in addition to the examples mentioned above, have looked at repurposing existing materials for circuit building. [3] is a toolkit of Figure 1. Method for making basic paper circuit: Plan magnetic circuit boards that cling to conductive painted the circuit, place conductive traces, connect components, traces, [17] looks at a variety of industrial shielding and add power. materials for electronically interactive pop-up scenes on paper, and [4] even embeds circuit elements within the pulp Plan the Circuit (optional) during the paper making process. While these were Decide where components will be organized on the page, techniques for handmade circuits, [14] presents a method and trace the component footprints. It is helpful to label for CNC vinyl-cutting copper foil tape to create circuit these footprints with their functionality and pinouts. Then boards and [20] presents digital design tools for making draw lines to indicate the necessary electronic connections. electronically interactive paper-based artifacts. These Using multiple colors helps keep traces organized. To techniques and explorations show the wide variety of connect external components to the page, draw traces to the existing and emerging material and techniques that page edge for alligator clips to attach. integrate circuits with paper. Add foil traces Electrified Books Cover the drawn traces with conductive foil tape. Make Finally, despite the growing trend in digitization, alligator clip pads for external components by folding researchers have become increasingly interested in conductive foil over the edge of the page. Connect multiple bridges, or even covering entire networks of traces with a foil pieces by soldering or folding over the end of the foil sheet of paper to create a new layer of blank space. and taping metal surface to metal surface. Connections made by simply sticking two foil tapes together, even those PAPER CIRCUITS WORKSHOPS with conductive