S. Prescesky et al., SILICON MICROMACHINING TECHNOLOGY FOR SUBNANOGRAM DISCRETE MASS RESONANT BIOSENSORS, Canadian journal of physics, 70(10-11), 1992, pp. 1178-1183
This paper describes a novel sub-nanogram discrete mass sensor with po
ssible biological applications including potential biomass monitoring
of living cells in culture. The sensing element is a micromachined sil
icon dioxide cantilever fabricated using a process compatible with com
mercial CMOS microelectronic processes. The 1 mum thick silicon dioxid
e device consists of two 8 x 150 mum cantilever arms supporting a 50 x
50 mum payload platform. Actuation of this first generation device is
performed using a small vibration table. Resonant amplitude are measu
red by detecting the angular shift of a laser beam incident on the dev
ice. Finite element analysis is used to model resonant frequencies. mo
de shapes, and frequency response. Cantilever resonates in fundamental
mode at 15.9 kHz and have an experimental mass sensitivity of 1.9 kHz
ng-1.