Figure 11.

Cross-section and surface stress of the tactile imager, (a) before object contact, (b) after object contact. (c) Detection principle of distributed hardness using pressure vibration; (c) Repulsive force distribution for ± PAC depending on local hardness, (d) Power spectrums of piezoresistor signal. Contact-force signal appears as the average around DC, while hardness signal appears at PAC. (e) Summary of measured performances (10 μm-thick sensing diaphragm). Reprinted/adapted with permission from Ref. [95]. Copyright 2007, IEEE.