Contact Pressure Level Indication Using Stepped Output Tactile Sensors

• Published in: Sensors (Basel, Switzerland) Vol. 16; no. 4; p. 511
• Main Authors: Choi, Eunsuk, Sul, Onejae, Kim, Juyoung, Kim, Kyumin, Kim, Jong-Seok, Kwon, Dae-Yong, Choi, Byong-Deok, Lee, Seung-Beck
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 09.04.2016; MDPI
• Subjects: Arrays; Contact; Contact pressure; Diaphragms; Digitization; Electrodes; Indication; Nanomaterials; Polyethylene terephthalate; Pressure sensors; Reproducibility; Sensors; Shear; Signal to noise ratio; spatially digitized electrode; Stepped; stepped output characteristics; tactile sensor; tactile sensor array; stepped output characteristics; spatially digitized electrode; tactile sensor; tactile sensor array
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s16040511

In this article, we report on a novel diaphragm-type tactile pressure sensor that produces stepwise output currents depending on varying low contact pressures. When contact pressures are applied to the stepped output tactile sensor (SOTS), the sensor's suspended diaphragm makes contact with the substrate, which completes a circuit by connecting resistive current paths. Then the contact area, and therefore the number of current paths, would determine the stepped output current produced. This mechanism allows SOTS to have high signal-to-noise ratio (>20 dB) in the 3-500 Hz frequency range at contact pressures below 15 kPa. Moreover, since the sensor's operation does not depend on a material's pressure-dependent electrical properties, the SOTS is able to demonstrate high reproducibility and reliability. By forming a 4 × 4 array of SOTS with a surface bump structure, we demonstrated shear sensing as well as surface (1 × 1 cm²) pressure mapping capabilities.