Rapid prototyping of force/pressure sensors using 3D- and inkjet-printing

Abstract

This work reports on inkjet- and 3D-printed force/pressure sensing devices. The employed printing processes can enable cost- and resource-efficient, fast and flexible designs compared to solid-state technology which is used as a reference design. The pressure sensing devices are realized as either 3D-printed steel or 3D-printed ceramic diaphragms. Both designs thus withstand harsh environmental conditions and elevated temperatures. Additionally, the increased size guarantees less sensitivity to dirt or moisture due to the larger diameter of the diaphragms. The hardware used for the capacitive sensor read-out is based on a shunt measurement system and subsequent demodulation. This architecture enables long cabling, allowing for large parasitic capacitances, without significant loss of transferred signal power, due to the employed power matching to the transmission line. Physical analyses such as contact angle measurements, profilometer measurements, and focused ion beam analysis are done to characterize the resulting printed surfaces. Then, the response of both designs is evaluated by applying force on the diaphragms surface using a moveable load cell. The gathered results are also compared to finite element method simulations.