Tactile feedback for teleoperation

In implementing tactile feedback, we are considering the problems of tactile transduction, signal processing, and tactile stimulation. While some of the problems--e.g. sensing--have been addressed in the past, tactile simulation or 'tactile display,' as an informational medium is yet at a very early stage of development. Our work has focused on the design of a 5 X 5 tactile display, and the fabrication problems surrounding high spatio-temporal resolution. Using pneumatic actuators and a mix of conventional and micromachining techniques, we have prototyped and characterized the display, and created a linked sensor-display system. The display was characterized in the usual manner of a linear system and the ability of human subjects to discriminate patterns, forces, and displacements was measured. The display was found to have a maximum force output of 340 milliNewton at each element, force resolution of 4.4 bits, and a frequency response of 7 Hz. Human subjects were able to recognize simple geometric patterns presented on the display, discriminant forces with 3.3 bits resolution, and sense displacements of 0.1 mm (5% of the array spacing).