To provide local shape information, an array of force generators can create a pressure distribution on a finger tip, synthesizing an approximation to a true contact. To implement tactile feedback, we are considering the problems of tactile transduction, signal processing, tactile display, and human perception. We have developed a prototype 5 by 5 pressure display with 3 bits of resolution and are developing a 1 mm square tactile sensor with 8 by 8 elements. One of our long-term goals is to fabricate a tactile sensing catheter which will allow surgeons to remotely feel tissue properties during minimally invasive surgery. It uses individually machined pins, with 5 atm pressure.
Advantages are ease of fabrication, no air leakage, and no pin friction.
As seen below, we can also mold curved compliant tactile displays. The limitations of human tactile perception need to be understood when designing a teletaction system. We model an ideal teletaction system simply using two elastic layers placed between the finger and an object. The tactile sensor layer transmits contact stress to a display layer. This system has no spatial sampling limits or level quantization, and allows us to study ideal information transmission, considering the effects of spatial anti-aliasing and reconstruction filters in the sensor and display respectively.