We present the design, fabrication, and testing of stretchable pressure sensing membranes. Two sensing techniques are demonstrated: resistive and capacitive. Both designs are incorporated in 400μm-thick films and are fabricated with thin film application of silicone and stencil/mask deposition of conductive materials. The resistive sensor utilizes room temperature liquid metal while the capacitive sensor utilizes multi-walled carbon nanotubes. Tests are performed with 18mm-diameter samples of each. Point load tests and acoustic response in an impedance tube provide feedback on sensor performance. The resistive sensor demonstrates a sensitivity of 0.045Ω/mm, and the sensor’s response has been characterized for in the 30Hz to 10kHz range with varying degrees of sensitivity. The capacitive sensor has a small point-load-deflection sensitivity ranging from 0.018pF/mm to 0.044pF/mm depending on capacitor diameter. Acoustic response are shown for 5Hz to 40 Hz, limited by external electronics. These devices are progress towards developing sensor networks capable of tracking aqueous turbulence.

Date Published: 27 March 2019
PDF: 14 pages
Proc. SPIE 10970, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2019, 109702D (27 March 2019); doi: 10.1117/12.2514358

Published in SPIE Proceedings Vol. 10970:
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2019
Jerome P. Lynch; Haiying Huang; Hoon Sohn; Kon-Well Wang, Editor(s)