Development of a force sensitive prosthetic finger

Abstract

Many modern prosthetic hands lack the ability to sense applied forces and those that do, often cannot accurately detect the location at which the force is acting, limiting the user’s feedback and dexterity. This project aims to create a practical force sensor for a prosthetic finger. The design consists of four strain gauges mounted on an internal beam structure enabling accurate detection of both force magnitude and location. The sensor was developed with careful attention to mechanical structure, signal processing and physical constraints for effective operation. A prototype sensor was fabricated, assembled and thoroughly tested to evaluate its performance. The results obtained from testing were critically analysed, followed by an extensive discussion about the sensor’s performance over different force and location ranges. Across all testing points, the median force uncertainty was ±2.36% and the median location uncertainty was ±1.87 mm. Overall, this project contributes to the advancement of tactile sensing in prosthetic fingers by demonstrating a compact, robust, and feasible sensor design capable of force and position detection. This supports the development of more functional and user-appropriate prosthetic hands with the potential to improve the quality of life of amputees.