CMOS tactile sensor systems

Tactile sensor systems based on complementary metal-oxide-semiconductor (CMOS) technologies have found a wide variety of applications covering various types of man-machine interfaces as well as industrial applications. These sensor systems are realized using commercially available CMOS processes combined with appropriate assembly technologies for advanced system packages, and dedicated micromachining processes to realize membranes or beam structures to improve the sensor sensitivity. Piezoresistive CMOS-based tactile sensor systems make use of implanted resistors and field-effect transistors (FETs) exploiting the piezoresistive effect in silicon. The applied CMOS chips extract the mechanical stress distribution in the chip surface which is characteristic for the corresponding mechanical loading of the CMOS chip or its package. This paper describes a three-dimensional force sensor used in metrology to extract the 3D geometry of precision machined parts, and the Smart Tooth, an innovative tool for orthodontic research and education.