Design and characterization of a photo-sensor based force measurement unit (FMU)

This paper presents the design and development of a customizable force measurement unit (FMU). The sensing mechanism is based on a monolithic structure incorporating a flexure with an interrupter and photo-sensors. The FMU is able to measure force by the deformation of the flexure, which results in a difference in the intensity of infrared light detected. Owing to the simplicity of the proposed structure and the sensing method, the FMU is an adaptable sensing platform with high design flexibility. We performed finite element method (FEM) simulations to systematically determine a set of design variables and characterized the static and dynamic properties of the fabricated FMU. We demonstrated that the FMU shows comparable performance to a widely used off-the-shelf sensor (Mini45, ATI) and can be used as a compact and accurate force sensor for various applications.

► The proposed force measurement unit (FMU) operates without the use of an external amplifier.
► The FMU is easily customized to various requirements such as capacity, size, and weight.
► The developed FMU was characterized through the experiments under static and dynamic loading conditions.
► The use of dual photo-sensors can effectively cancel out the interference generated by the shear forces.
► The results show comparable performance of both conditions to a widely used off-the-shelf sensor.