Piezoresistive load sensor
AssigneeThe Governors of the University of Alberta
InventorsDavid Benfield, Walied Ahmed Mohamed Moussa
Life of this patent
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Abstract
A three-axis load sensor utilizing four piezoresistive devices on a flexible silicon membrane is provided. The load sensor further includes a mesa disposed on the membrane substantially equidistant from the piezoresistive devices. A six-axis load cell is provided by placing a plurality of load sensors disposed on a substrate, the substrate configured to attach to an object wherein forces applied to the object can be measured and/or determined. The load sensors can be manufactured using bulk microfabrication techniques on a single crystal silicon wafer, and can detect normal and shear loading applied to the membrane.
Claims22
A microelectromechanical system (“MEMS”) load sensor for detecting loads in three axes, the load sensor comprising:
- a) a flexible silicon membrane substrate comprising a top surface;
- and
- b) a plurality of piezoresistive devices disposed on the top surface, the piezoresistive devices disposed in a spaced-apart configuration around a perimeter of the top surface, each piezoresistive device configured to produce an output voltage.
A load cell for detecting loads in six axes, the load cell comprising:
- a) a load cell substrate configured for disposition on an object;
- b) a plurality of microelectromechanical system (“MEMS”) load sensors for detecting loads in three axes disposed on the load cell substrate, each load sensor further comprising:
- i) a flexible silicon membrane substrate comprising a top surface, and
- ii) a plurality of piezoresistive devices disposed on the top surface, the piezoresistive devices disposed in a spaced-apart configuration around a perimeter of the top surface, each piezoresistive device configured to produce an output voltage.
17-19. (canceled)
A load cell system for detecting loads in six axes, the system comprising:
- a) a load cell substrate configured for disposition on an object;
- b) a plurality of microelectromechanical system (“MEMS”) load sensors for detecting loads in three axes disposed on the load cell substrate, each load sensor further comprising:
- i) a flexible silicon membrane substrate comprising a top surface, and
- ii) a plurality of piezoresistive devices disposed on the top surface, the piezoresistive devices disposed in a spaced-apart configuration around a perimeter of the top surface, each piezoresistive device configured to produce an output voltage;
- and
- c) means for combining or multiplexing the output voltages from the plurality of piezoresistive devices.
23-31. (canceled)
Dependencies are inferred from the claim text.