Battery-powered, wireless MEMS sensors for high-sensitivity chemical and biological sensing

• Main Authors: Britton, C.L., Warmack, R.J., Smith, S.F., Oden, P.I., Jones, R.L., Thundat, T., Brown, G.M., Bryan, W.L., Depriest, J.C., Ericson, M.N., Emery, M.S., Moore, M.R., Turner, G.W., Wintenberg, A.L., Threatt, T.D., Hu, Z., Clonts, L.G., Rochelle, J.M.
• Format: Conference Proceeding
• Language: English
• Subjects: Biological information theory; Biosensors; Chemical and biological sensors; Chemical processes; Gold; Hydrogen; Laboratories; Micromechanical devices; Palladium; Wireless sensor networks
• ISSN: 1522-869X; 2332-5801
• DOI: 10.1109/ARVLSI.1999.756060

Researchers at Oak Ridge National Laboratory (ORNL) are developing selectively coated cantilever arrays in a surface-micromachined MEMS process for very high sensitivities in chemical and biological sensing. Toward this end, we have developed a one-dimensional (1-D) 10-element microcantilever array that we have coated with gold for mercury sensing and palladium for hydrogen sensing. Ultimately we will coat each element with a different coating. Currently, measurements have been performed using a companion analog 1.2-/spl mu/m CMOS eight channel readout chip also designed at ORNL specifically for the microcantilever arrays. In addition, we have combined our sensors with an ORNL-developed RF-telemetry chip having on-chip spread spectrum encoding and modulation circuitry to improve the robustness and security of sensor data in typical interference- and multipath-impaired environments. We have also provided for a selection of distinct spreading codes to serve groups of sensors in a common environment by the application of code-division multiple-access techniques. Our initial system is configured for use in the 915-MHz Industrial, Scientific, and Medical (ISM) band. The entire package is powered by four AA batteries.