The German Patent and Trade Mark Office published the new patent DE 10 2018 127 320 A1 on 7 May 2020. The invention by Oliver Völckers, Christoph von Brockhusen and Jergus Majernik describes a force sensor consisting of a flexibly deformable material such as rubber.
Quote from the patent specification (translated):
[0061] Conventional sensor arrangements based on foils with so-called force sensing resistors, when used as sole sensors, provide signals with jitter interference in the frequency range of over 20 Hz, which must be filtered out separately. The cause is the strong vibrations when walking, which lead to alternating contacts of the film...
[0062] In contrast, the spring deflection, i.e. the triggering deflection, of the solution according to the invention is in the range of 0.5 mm, which is 10 to 50 times as much as that of conventional sensors based on a force sensing resistor.
Link to Google Patents with PDF
English version: https://patents.google.com/patent/DE102018127320A1/en
German version: https://patents.google.com/patent/DE102018127320A1/
Title:
Flat sensor arrangement for temporally and / or spatially resolved force or pressure measurement
Abstract (translated from German)
A flat sensor arrangement (1) for temporally and / or spatially resolved force or pressure measurement is disclosed. This sensor arrangement (1), distributed over a detection area, contains individual sensors. It also contains a controller with which the sensors are connected. The sensors are each formed with a first sensor part (5) and a second sensor part (8). The first sensor part comprises a printed circuit board (4) on which, in the area of a detection area, a printed conductor structure is applied, which is exposed to a contact surface. The conductor track structure has an electrical resistance and can be connected to two electrical poles of a measuring current source. The second sensor part (8) contains a contact element formed from a flexibly deformable material. The contact element has a contact surface with which it lies opposite the detection surface of the first sensor part and which tapers in a cross-sectional extent starting from a base in the direction of the detection surface. The contact element is also at least electrically conductive along the contact surface. Such a sensor arrangement (1) is particularly reliable and allows the possibility of accurate measurements while remaining stable over a long period of use. It is also inexpensive to manufacture, requires little maintenance and is easy to use for the user. A special application of the sensor arrangement (1) is to integrate it in an insole or insole for a shoe.