Materials Science

Tiny Gas Sensors

See allHide authors and affiliations

Science  04 Jan 2002:
Vol. 295, Issue 5552, pp. 15
DOI: 10.1126/science.295.5552.15b

One aspect of the development of smaller microelectromechanical systems has been the creation of low-powered chemical sensors. For solid-state gas sensors, an active ceramic layer is used for the detection, which typically is fabricated with a thin-film deposition technique such as screen or ink jet printing. Using a combination of soft lithography and photolithography and a suspension of tin oxide particles, Heule and Gauckler create a sensor element on the micrometer scale, which is about two orders of magnitude smaller than current designs. The polymer template was placed on the substrate to form fine channels, which were then filled via capillary action. The ceramic particles were sintered and then connected to the device via platinum contacts. The tin oxide device showed sensitivity to both hydrogen and carbon monoxide down to 100 and 600 parts per million, respectively. It is envisioned that a variety of doped and undoped ceramics can be placed onto a single device to create a sensor array that would replace single gas sensors. — MSL

Adv. Mater.13, 1791 (2001).

Navigate This Article