Positon Sensors
The sensors, developed by AMG-Technology, comprise two rigid parts: a single anchored (1) and a single movable (2) part, respectively, as illustrated in Fig. 1(a) in different grey colors. These devices can operate in ±X and ±Y directions. In order to transduce the movement of the part (2) in respect to the part (1) without backlash, loose move and creep, a single or plurality of monolithic flexures (3) are made available as schematically shown in Fig. 1(b). Since the silicon - material for the MEMS sensors is a non-stretchable, to provide permanent connection between both mentioned parts compliant mechanisms with corrugated elements which bend during the movement are provided. Flexures’ bending causes mechanical stress and strain, thus by detection of the signals from strain-sensing elements located in relevant areas, the relative position of the both parts can be monitored. The contact points of the flexures to the both parts of the MEMS sensor are permanent and sensing piezoresistors, positioned in the in areas of highest strain at the fixed end of detecting cantilevers, provide the required high sensitivity.
(a) (b)
Figure 1. (a): Conceptual layout of a MEMS sensor with single anchored (1) and single actuated (2) part moveable in ±X and ±Y direction; (b): layout of a MEMS sensor with a flexure (3) which detects X-Y displacement of the actuated member (2) in respect to the anchored one(1);
The sensors are characterized with excellent linearity (Fig.2)
Figure 2. Linear fit of the sensor displacement
Specs
Applications
- precision mechanics
- ultra-precise alignment in microelectronics
- data storage
- deformation control (bridges, buildings)
- active control of optical systems
