A flexible capacitive tactile sensor array with micro structure for robotic application

A flexible capacitive tactile sensor array with micro needle structure is proposed in this paper for robotic application. Micro needle layer made of polydimethylsiloxane (PDMS) is sandwiched between the upper electrode layer made of PDMS and the bottom electrode layer fabricated on polyester (PET) film. The PDMS material renders the device adequate flexibility as it can be rolled into a cylinder. The single cell size in the fabricated 4 × 4 sensors array is 0.7 × 0.5 cm2 and the initial capacitance of each cell is 0.86 pF. The fabricated cell shows a sensitivity of 3.26%/mN within the full scale range of 1 kPa. The micro needle structure gives better repeatability and stability. The maximum error during each measurement is about 3.2%, while the minimum error is about 1.2%.