Sewing Up Science

Abstract

Traditionally, many teachers have used breadboards and alligator clips to teach students about circuits and electricity. Electronic textiles (e-textiles)--fabrics embedded with electrical or electronic components--offer a new model for teaching this content. E-textiles also engage students in programming and engineering design through non-traditional projects and materials. Evidence suggests designing e-textile projects helps students change their ideas about who can participate in engineering, often developing new identities strongly associated with science and technology (Kafai, Fields, and Searle 2014; Barton, Tan, and Rivet 2008). Unit description This article describes a four-week electricity curriculum using three e-textiles projects that encompass 10 specific content lessons to cover concepts of electron transfer, electricity, circuits (simple, series, and parallel), conductivity and resistance, and short circuits. The first project introduces students to designing and constructing simple circuits using copper adhesive tape and LED lights on paper (Figure 1, p. 46). Next, students design and sew bracelets that incorporate a parallel circuit using conductive thread and LED lights (Figure 2, p. 46). In the third project, students choose their own product to design, incorporating preprogrammed, sewable microcontrollers to sequence the flashing of LEDs, focusing students' efforts on issues of short circuits and polarity (Figure 3, p. 47). The project timeline accommodates time for both lesson instruction and project work (Figure 4, p. 48). Objectives Lessons open with a brief lecture, discussion, and review of the prior day's material followed by hands-on application of the concepts. Each project was designed to cover specific education standards and to be flexible, so teachers can select any combination of projects to suit class time and budget. Focal concepts and necessary supplies are listed in Figure 5 (p. 48). Project 1: Paper circuits In this activity, students use copper tape and LEDs with a small coin cell battery to create a light-up circuit on paper. It uses readily available and inexpensive materials to mirror projects in the Circuit Sticker Sketchbook (see On the web). In the first part of the activity, students follow a pre-drawn pathway to create the circuit. They use two pieces of copper tape for the positive and negative lines of the circuit. Taping the wire leads of an LED between the two copper tape pieces requires students to identify the positive and negative sides of the LED. After completing the basic circuit, students design a new circuit using the copper tape in a decorative fashion or drawing a picture that incorporates the illuminated LEDs. Through such customization, students create their own learning challenges as they encounter needs for series--and in some cases, parallel--circuits to accommodate high-resistance LEDs. [FIGURE 1 OMITTED] [FIGURE 2 OMITTED] Project 2: Bracelets In the bracelet projects, based on Lovell and Buechley's (2010) published guide Getting Hands-On with Soft Circuits (see On the web), students use conductive thread to sew three LEDs in parallel with a set of snaps that act as a switch for the circuit (see On the web for a link to the Light-Up Bracelet Student Guide). Students all create the same project with the same circuit design, but they personalize their designs (Figure 2). Students face several conceptual challenges in this project. First, conductive sewing is different from traditional sewing, so they learn to sew (by hand) a solid electrical connection rather than simple attachment to fabric. Second, the conductive thread has a natural resistance, which is less forgiving with higher energy LEDs, meaning that multiple types of errors (such as wires burning out or mis-sewn stitches) can lead to LED failure. (Note: We use Sparkfun's four-ply stainless steel thread. …