Silicon force sensor
| DWPI Title: Load sensing system for measuring high load shock rate, has load application component which applies compressive preload to load sensor, and effects relaxation in compressive load on piezoresistive sensor under operational load |
| Abstract: The various technologies presented herein relate to a sensor for measurement of high forces and/or high load shock rate(s), whereby the sensor utilizes silicon as the sensing element. A plate of Si can have a thinned region formed therein on which can be formed a number of traces operating as a Wheatstone bridge. The brittle Si can be incorporated into a layered structure comprising ductile and/or compliant materials. The sensor can have a washer-like configuration which can be incorporated into a nut and bolt configuration, whereby tightening of the nut and bolt can facilitate application of a compressive preload upon the sensor. Upon application of an impact load on the bolt, the compressive load on the sensor can be reduced (e.g., moves towards zero-load), however the magnitude of the preload can be such that the load on the sensor does not translate to tensile stress being applied to the sensor. |
| Use: Load sensing system for measuring high load shock rate, and for validating modeling and simulation tools. |
| Advantage: The sensor design facilitates control of a stress level at the silicon (Si) sensor die and thus the effective load range of the sensor, while maintaining a high signal-to-noise (S/N) ratio. The input ground and Voutput can be connected to simplify circuit design and minimize noise, which can effectively create a voltage divider circuit. Flexibility at the edge of plate reduces stress, increases maximum achievable load, and reduces signal output. The sensing element can be placed in a containing structure which can protect the sensing element as well as also containing other material components which can minimize impact stresses that can cause fracture of the sensing element. |
| Novelty: The load sensing system (100) has load sensor (120) comprising piezoresistive sensor (122), and load application component which locates load sensor on supporting structure, applies compressive preload to load sensor resulting in application of compressive load to piezoresistive sensor, and effects relaxation in compressive load on piezoresistive sensor under operational load. The load application component comprises nut (140) and bolt (130). The bolt comprises bolt head (131) and bolt shaft (133) having threaded portion (135) to which nut can be attached. |
| Filed: 10/28/2013 |
| Application Number: US14064573A |
| Tech ID: SD 12578.0 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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