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In this paper, we present the development of a 10  ×  10 sensing element capacitive flexible pressure and tactile sensing array for normal stress measurement for wearable device applications. The sensor array combines micro-fabricated polydimethylsiloxane (PDMS) structures and a flexible printed circuit board (FPCB) with 100 µm thick polyimide as substrate. Each sensing element has one Cr/Au floating electrode embedded in the PDMS, two Cu/Au sensing electrodes on the FPCB and two Cu electrodes embedded underneath in the FPCB for electromagnetic shielding to isolate the environmental influence from the surface where the sensor patch is placed. The PDMS based pressure sensing membrane inbetween the floating electrode and sensing electrodes was specifically designed and fabricated. The thickness of the sensing membrane ranged from 0.6–1.3 mm. To increase the device sensitivity a membrane with micro-pillar was also selected. Membrane with various structures, different micro-pillar height and without pillar were fabricated and characterized. Two sensing elements with different sizes but the same pitch on the sensors were compared, regarding the device sensitivity, sensing range and the cross-talk influence of the sensing elements. Results from 16 devices with different structures were obtained. Lastly, the hysteresis effect of the sensor and temperature influence was tested and analyzed. The corresponding 10  ×  10 scanning circuits were implemented and the 100 sensing measurement results were displayed in 0.8 s periods in real time. The developed pressure/tactile sensors with different sensing range and sensitivity provide a guide for the design and selection of pressure/tactile sensing devices with a variety of applications.

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