Method and system for electronic detection of mechanical perturbations using BIMOS readouts
A sensor for detecting mechanical perturbations represented by a change in an electrical signal includes a structure such as a cantilever, membrane, etc. and a field effect transistor such as a MOSFET embedded in the structure. The drain current of the embedded transistor changes with mechanical perturbations in the structure caused, for example, by a bio-chemical interaction being sensed. A scanning probe microscope utilizes the embedded MOSFET with a BiMOS actuator.
1. A sensor for detecting mechanical perturbations represented by a change in an electrical signal comprising:
a cantilever structure;
a BiMOS embedded in the cantilever structure, the BiMOS including a metal-oxide semiconductor field effect transistor measuring deflection of the cantilever and a bipolar transistor providing an amplified signal;
a piezo-actuator on or embedded in the cantilever structure to provide bending of the cantilever structure; and
a feedback circuit responsive to the signal from the BiMOS to control the piezo-actuator.
2. A sensor for detecting mechanical perturbations represented by a change in an electrical signal as recited in claim 1 wherein said cantilever is an Si cantilever.
3. A sensor for detecting mechanical perturbations represented by a change in an electrical signal as recited in claim 2 wherein the feedback circuit is responsive to the transistor's electrical signal to adjust a voltage applied to the piezo-actuator.