SBIR Phase I: High Sensitivity Micro Strain Sensor Using Magnetostrictive Spin Dependent Tunneling Materials

Nve Corporation, Eden Prairie MN

Investigators

Abstract

This Small Business Innovation Research (SBIR) Phase I project seeks to demonstrate a test strain sensor in microchip form using magnetostrictive spin dependent tunneling materials. Silicon piezoresistive materials have high sensitivity but operate at low temperatures, whereas metallic films have much better temperature capability but much lower sensitivity. The limitations in sensitivity/temperature, susceptibility to ESD, cost, and others have precluded the technology to be used in several key commercial and military applications. An approach based on the high sensitivity, wide temperature range, low power, small size and low cost of similar devices is proposed. Although as a magnetic device, the sensor will be insensitive to external magnetic fields of practical magnitude, using a proprietary approach. The feasibility will be demonstrated by fabricating test devices; constructing a miniature strain tester; and achieving high strain sensitivity. It is expected that these sensors will find rapid initial acceptance in application areas of industrial control, civil engineering projects, and robotics, and then expand to other applications. This sensor will function under very adverse conditions of temperature, ESD and radiation. Unlike other magnetic sensors the device will have no response to magnetic fields, either natural or created by the equipment it is trying to control. Because the sensor is manufactured by microelectronics techniques it will be low cost and the packaging requirements will not have to include many of the techniques employed today to "safeguard" the existing sensor.