A pressure-sensitive impedance-type touch panel which detects impedance of sensors to identify touch position and applied pressure is demonstrated. It shows high pressure sensitivity in the low pressure regime, high water-resistance, low hysteresis, and high durability, and enables multilevel pressure detection. Because impedance-type sensors act as touch sensors as well as pressure sensors, fabrication process and device architecture can be simplified. Two substrates of the touch panel are bonded together without spacers or bezel tapes in between, improving the uniformity of compressive strain in current pressure-sensitive touch panels. The touch solution offers a new measurement mechanism for sensors involving non-conductive to conductive transition and has great potential for application in wearable interactive devices.
Liu, S-Y., Pan, J., & Shieh, H-P. (2018). A Pressure-Sensitive Impedance-Type Touch Panel With High Sensitivity and Water-Resistance. Ieee Electron Device Letters, 39(7), 1061-1064. https://doi.org/10.1109/LED.2018.2833453