On Thu, 13 Jun 2002, Alan B. Pearce wrote:

> I would suggest getting the sculpture done as a matrix of wires, possibly
> fairly open, and then driving some wires with signals, and using other wires
> as detectors, a bit like a massive keyboard matrix.
>
> I do not know how well the interaction between the driven wire and detection
> wire would be with just placing a hand on it is, you may have to experiment
> to find out. Get your artist friend involved in this so she has a good idea
> of what is needed for the sculpture.

If you happen to have one of Synaptic's(*) TouchPads lying around, then
try cutting off the PCB traces that are connected to the TouchPad and
wiring them to this wire Matrix. It then should be possible to sense the
hand position and move a cursor around on a CRT. The API for the TouchPad
is exposed (for Window's) in such a way that you could write custom
software to capture the packets coming the TouchPad and interpret that
information anyway you see fit.

The biggest challenge will be in constructing a mesh that has similar
impedance as a TouchPad. You probably can do this with some 30AWG magnet
wire limited to < 1 meter lengthes. Each wire needs to be almost the same
length so that the capacitance matches quite closely.

(*) I work for Synaptics.

Scott

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