Vincent Leclerc & Joey Berzowska

These sleeves are sensitive to physical contacts. When users flex or cross their arms, a sound is synthesized within the sleeves and output through miniature flat speakers. The idea is pretty straightforward: using very simple elements (metallic organza and conductive yarns) we created a flex and touch sensor made of hundreds of switches.

The stripes of metallic organza are sequentially disposed so that they are connected either to ground or to a pin of the micro controlling unit. When a 'pin' stripe is grounded on a 'ground' stripe, it issues a signal to the mcu and the latter reacts accordingly.

The whole circuit is stitched on fabric. We had to conduct many experiments to figure out what type of stitches were the most solid and less electrically resistive. The approach We adopted is a combination of fine and loose stitches overlapped with wide and stretched ones. The stitched circuit board connects every element to the very few 'hard' parts of the system: a PIC16F84A, a 3V watch battery and speakers. The connections to the PIC are done using conductive epoxy so there are no (fragile) solder connections anywhere. Same goes for the miniature flat speakers and the battery.

We programmed the PIC using the CCSC compiler. Here is the C source of the program. It uses a library (v_tones.c) that I modified from CCS' tones.c. It also uses CCS' stdlib.h. We cannot distribute those due to copyright issues... Basically what the code does is sweeping from one frequency to another depending on the number of contacts made on the sleeves. There is an idle state (no sound) when the number of contacts doesn't change.

Get in touch with Vincent for more info.

14-02-2005 Many people are sending emails asking for technical info about materials and methods. Here are some answers to your questions..

Conductive Yarns
There are dozens of different ones with different electrical, mechanical and chemical properties. Google for Aracon and Bekintex or bring your multimeter to your local Indian fabric store and test the shiny stuff (they usually get really excited when you tell them that you can use their fabric/yarns to make electronics and will direct you to others suppliers & resources).

Conductive Epoxies
McMaster-Carr or ABRA have some silvered-filled epoxies and Devcon makes TRU-BOND 215, a copper-filled epoxy ( We've never tried it though. Also, we never did any empirical testing of the mechanical endurance of the epoxy.

Attaching Yarns to ICs
There are many ways to do this. The simplest one involves making a simple PCB with largeish through-hole solder pads and 'threading the pads' with your conductive yarns - just like you would do to attach a button to a shirt. Then, a small drop of silvered-filled or copper-filled (cheaper) epoxy ensures a good mechanical and electrical bond.