Abstract
This study presents a three by three flexible tactile sensor array using stretchable silicon spring with doping silicon. Each tactile sensor device is located at the silicon-unit of a 2D chip-network distributed, which are mechanically and electrically connected to surrounding devices by stretchable silicon spring. The doping silicon acts as a piezo-resistive sensing element embedded into the membrane located at the center of unit, which can detect normal force without heat interference by Wheatstone bridge. The springs can stretch and expand the tactile sensor by several times of magnitude area forming a variable-density network of interconnected devices. There are four merits of this approach. (1) Using existing process technologies and materials for semiconductor could simultaneously complete the tactile sensor and spring structure without assembling problem. (2) Spring structure lets the tactile sensor array have the tunable spatial resolution by changing the distance between each unit. (3) Wheatstone bridge on silicon membrane has a large sensing range in normal force without interference of temperature by fully differential design. (4) The tactile-network with flexibility can be applied to curved surfaces and stretchable application.