Fabric Prototyping Board - Xiao Xiao
Bendy breadboard for for flexible conductive components
Motivation
Traditionally, we do electronics prototyping on breadboards with wire to connect components together. While breadboards and wire is a useful way to quickly design circuits, what we design on them doesn't translate directly to soft circuits because of the vastly different properties between wire and conductive thread. Furthermore, the topography of a circuit made on a breadboard can often be very different from the same circuit sewn with conductive thread. In order to make a circuit with conductive threads and fabrics, we go through a laborious process of sewing the circuit or the difficult to reverse process of ironing on components. I wanted to create a tool for user to easily experiment with circuits made from conductive fabrics and threads.
Design
My fabric is inspired by rubber band pegboard toys. I wanted a flexible material with metal rods sticking out so that you can wind conductive thread around the rods to guide them and to create connection nodes. Additionally, traditional electronic components can also attach to the rods by having their legs twisted around.
Process
I made the base fabric from casting silicone. While the silicone is drying, I embedded bolts into the mix in a grid array. The grid is made from 8 alternating rows of 8 or 7 pegs, having 60 pegs total.
Demo
I attached a battery and made two separate circuits on my board, each lighting up a single LED and activated by a switch made from a piece of conductive fabric. The ends of the conductive thread is tied to pegs, and its length makes a path through the board by winding on anchor pegs. The legs of the LEDs hook around pegs to attach to them. To secure some of the nodes, I put a nut on the bolts.
Lessons Learned
- It was actually harder than I thought to tie the conductive thread to the pegs, possibly because I used the stiffer 40ply thread as opposed to the 20ply. In the future, I would like to explore easier ways of securing the ends of the threads.
- I liked how my board lets users see the topography of circuits more clearly than on a breadboard. However, I wonder if the fixed spacing of the pegs may limit the shape of circuits that people make. I'd like to explore systems that allow for more flexibility in circuit topography design.
- Another thing I'm trying to think about is how to integrate "snap-on" ICs onto fabric prototyping boards