Patent ID: 6204544
Filing Date: 2001-03-20
Classification: G01P

Abstract:
A microactuator comprising an actuator and a field effect transistor; wherein said transistor comprises a source, a drain, a gate, and an insulator; and wherein:(a) at least one surface of said source and at least one surface of said drain are coplanar, wherein the coplanar region between these surfaces of said source and said drain is defined to be the channel of said transistor;(b) said insulator covers the channel;(c) said gate is laterally movable in a plane that is parallel to the channel of the transistor, such that the portion of the channel that is covered by said gate varies as said gate moves in this parallel plane, and such that at least a portion of said gate covers said source, and such that at least a portion of said gate covers said drain;(d) when at least a portion of said gate covers the channel, then a voltage on said gate beyond a pre-determined threshold voltage, in conjunction with a voltage between said drain and said source, induces a drain current between said source and said drain; wherein the drain current is a linear function of the portion of the channel that is covered by said gate; and(e) said gate is connected to said actuator, whereby the drain current measures the position of said gate and of said actuator.