The Touch Board is a circuit board by Bare Conductive that allows you to create a variety of capacitive touch sensitive devices.
This allows for everything from quick an easy prototyping of accessible instruments in the classroom of music session, through to being central to a full instrument design as Human Instruments have done.
As it is capacitive you can use just one terminal (unlike the Makey Makey), and you can run it as proximity sensitive.
This means you can hide the switch behind plastic, which helps with hygiene and circumnavigates questions about the safety of 5v with medical implants.
We are working on a guide and video, but for now have a look at the excellent Touchboard resources below.