This work presents piezoelectric oxide semiconductor field effect transistor ͑POSFET͒ based touch sensing devices. These devices are fabricated by spin coating thin ͑ϳ2.5 m͒ piezoelectric polymer film directly on to the gate area of metal oxide semiconductor ͑MOS͒ transistor. The polymer film is processed in situ and challenging issues such as in situ poling of piezoelectric polymer film, without damaging or altering the characteristics of underlying MOS devices, are successfully dealt with. The POSFET device represents an integral "sensotronic" unit comprising of transducer and the transistor-thereby sensing as well as conditioning ͑and processing͒ the touch signal at "same site."

This paper presents the research on tactile sensing\ud system on chip. The tactile sensing chips comprise of 5 5 array\ud of Piezoelectric Oxide Semiconductor Field Effect Transistor\ud (POSFET) devices and temperature sensors. The POSFET devices\ud are obtained by spin coating piezoelectric polymer, poly(vinylidene\ud fluoride-trifluoroethylene) (P(VDF-TrFE)), films directly on to the\ud gate area of Metal Oxide Semiconductor (MOS) transistors. The\ud tactile sensing chips are able to measure dynamic contact forces\ud and temperatures. The readout and the data acquisition system\ud to acquire the tactile signals are also presented. The chips have\ud been extensively tested over wide range of dynamic contact forces\ud and temperatures and the experimental results are presented.\ud The paper also reports the research on tactile sensing chips with\ud POSFET array and the integrated electronics

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This paper presents the advanced version of novel piezoelectric oxide semiconductor field effect transistor (POSFET) devices-based tactile sensing chip. The new version of the tactile sensing chip presented here comprises of a 4 × 4 array of POSFET touch sensing devices and integrated interface electronics (i.e., multiplexers, high compliance current sinks, and voltage output buffers). The chip also includes four temperature diodes for the measurement of contact temperature. Various components on the chip have been characterized systematically and the overall operation of the tactile sensing system has been evaluated. With new design, the POSFET devices have improved performance [i.e., linear response in the dynamic contact forces range of 0.01-3 N and sensitivity (without amplification) of 102.4 mV/N], which is more than twice the performance of their previous implementations. The integrated interface electronics result in reduced interconnections which otherwise would be needed to connect the POSFET array with off-chip interface electronic circuitry. This paper paves the way for CMOS implementation of full on-chip tactile sensing systems based on POSFETs.

This work presents fabrication and evaluation of novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing chip. In the newer version presented here, the tactile sensing chip has been fabricated using CMOS (Complementary Metal Oxide Semiconductor) technology. The chip consists of 4 x 4 POSFET touch sensing devices (or taxels) and both, the individual taxels and the array are designed to match spatiotemporal performance of the human fingertips. To detect contact events, the taxels utilize the contact forces induced change in the polarization level of piezoelectric polymer (and hence change in the induced channel current of MOS). The POSFET device on the chip have linear response in the tested dynamic contact forces range of 0.01-3 N and the sensitivity (without amplification) is 102.4 mV/N.

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