Lisa's lower half has three sensors--two in the back (stars), and one in the front. Unlike the other sensors, Matt and Kyle chose to make the front sensor act as a nonlinear playhead marker within the Max/MSP software environment, allowing for Lisa's audio output to be scrubbed and scratched like a digital turntable.
Constructing your own foreplay robot may seem like a lot of work, but the real genius is programming the software. Matt's Max/MSP Moaning Lisa patch took over a year to develop and uses neural networking algorithms to make Lisa's interaction as nuanced and unpredictable as Matt's real life experiences.
Lisa's hardware communicates to Matt's computer using a USB connection near her ankle. Because the Make controller inside Lisa is in open-source development, Matt and Kyle will use this USB connection to upgrade her firmware down the road.