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. (C) 2012 Elsevier B.V. All rights reserved.