An actuated instrument, the Feedback Lap Steel can put energy into the strings by physically vibrating them. It has an RCA jack input which can be driven by an audio amplifier which goes into the tactile transducer with the bridge mounted directly to it. By taking the output through some processing and back into the input you get a feedback loop with some control.
This instrument was built using basic hand tools based on some online DIY Lap Steel instructions. The exception to the hand-built part is the bridge which was laser cut out of 1/2″ acrylic. The body was made out of a piece of 2×6 redwood decking lumber.
Performance at CCRMA Spring Concert 2012