Device for measuring deformations, stresses, forces and/or torques in a plurality of axes with a sensor chip attached to a rear side of a base plate below a force conductor
An apparatus for measuring deformations, stresses, forces and/or torques of an object includes a spring body and a sensor chip, which includes one or more sensor elements for measuring a deformation, stress, force and/or a torque as well as an electronic circuit on a substrate. The spring body includes a base plate on the front side of which a force conductor, preferably in the form of a pin, is installed, the sensor chip being positioned on the rear side of the base plate below the force conductor. Also disclosed a system including the apparatus and a data processing unit, wherein the data processing unit is configured for reading out measured data detected by the sensor chip and preferably detects the forces and/or torques acting on the force conductor based thereon.
1 . An apparatus for measuring multi-axis loads on an object comprising:
a spring body, and
a sensor chip comprising one or more sensor elements configured to measure deformations, stresses, forces and/or torques and an electronic circuit on a substrate, wherein the spring body comprises a base plate on the front side of which a force conductor is installed, wherein the sensor chip is positioned on and attached to the rear side of the base plate below the force conductor,
wherein the spring body is configured such that forces and/or torques acting on the force conductor are concentrated in a localized area of the base plate to which the substrate of the sensor chip is connected and which translate into deformations or stresses of said substrate of the sensor chip and wherein the one or more sensor elements are configured to measure the deformations or stresses of the substrate of the sensor chip to allow for conclusions to be drawn about forces and/or torques acting on the force conductor.
2 . The apparatus according to claim 1 , wherein the force conductor is formed by a pin which is substantially perpendicular to the base plate when no force is exerted upon it.
3 . The apparatus according to claim 2 , wherein the pin has a diameter from 0.5 mm to 5 mm, a length from 5 mm to 500 mm, and/or an aspect ratio of diameter to length from 1:3 to 1:100.
4 . The apparatus according to claim 2 , wherein the pin has a central bore.
5 . The apparatus according to claim 1 , wherein the base plate has a thickness between 0.1 mm and 2 mm.
6 . The apparatus according to claim 1 , wherein the base plate and/or the force conductor has a relief groove, in the form of a border around the area where the force conductor comes into contact with the base plate.
7 . The apparatus according to claim 1 , wherein the base plate and/or the force conductor are formed from a metal.
8 . The apparatus according to claim 1 wherein the one or more sensor elements are configured for a resistive, optical, magnetic, inductive and/or capacitive measurement of deformations, stresses, forces and/or torques of the substrate.
9 . The apparatus according to claim 1 wherein the one or more sensor elements comprise piezoresistive structures, and/or the sensor chip has more than 5 sensor elements, the sensor elements having different sensitivities for a measurement of deformations, stresses, forces and/or torques of the substrate.
10 . The apparatus according to claim 1 wherein the sensor chip is configured to measure deformations, stresses, forces and/or torques in multiple axes and/or to measure a two-dimensional distribution of deformations, stresses, forces and/or torques of the substrate.
11 . The apparatus according to claim 1 wherein the substrate of the sensor chip comprises a semiconductor material.
12 . The apparatus according to claim 1 wherein the substrate of the sensor chip has a thickness between 100 μm and 600 μm.
13 . A system comprising:
a) an apparatus according to claim 1 , and
b) a data processing unit, wherein the data processing unit is configured for reading out the measured data detected by the sensor chip.
14 . A system according to claim 1 wherein the data processing unit is configured to detect the forces and/or torques acting on the force conductor from the measured data related to deformations, stresses, forces and/or torques of the substrate detected by the sensor chip.
15 . The apparatus according to claim 7 , wherein the metal is selected from the group consisting of iron, steel, stainless steel, spring steel, brass, copper, titanium, aluminum, lead, magnesium, beryllium copper and an alloy of the aforementioned.
16 . The apparatus according to claim 1 wherein the one or more sensor elements are configured for a piezoresistive measurement of deformations, stresses, forces and/or torques of the substrate.
17 . The apparatus according to claim 9 wherein the one or more sensor elements comprise piezoresistive sensor bridges.
18 . The apparatus according to claim 11 , wherein the semiconductor material is selected from the group consisting of silicon, monocrystalline silicon, polysilicon, silicon dioxide, silicon carbide, silicon germanium, silicon nitride, nitride, germanium, carbon, gallium arsenide, gallium nitride and indium phosphide.