Patent attributes
Aspects described herein provide structures for a force sensor, and force sensors using such structures, which are compact and easy to manufacture, for example by 3D printing. In particular the structures comprise a pair of stacked ring sensor elements, the ring sensor elements in turn being formed by upper and lower ring elements joined together at points around the circumference thereof by resiliently mounted connection bars. The connection bars may extend in the same plane as the rings, in which case sensitivity to torque about the axis of the rings is much reduced, such that a five-axis sensor is effectively obtained, or the connection bars may extend obliquely between the upper and lower rings of each sensor element, such that they have a directional component in the direction of the axis of the rings (the rings of each element being co-axially stacked). In this second case application of a torque about the ring axis causes the oblique connection bars to either increase or decrease their directional component in the axial direction, thus providing sensitivity to torque about the axis, and providing a compact six axis sensor.
