Bio-inspired Design of a Soft Bending Actuator for Flexion of a Human Index Finger: A Case Study

This work proposes a bio-inspired design of a soft pneumatic actuator where air chambers are located only in specific bending points. An image analysis was conducted to analyze the trajectory of the tip of the author's index finger. This analysis aimed to determine the dimensions that should be used in the actuator. The actuator was then modeled as a three–rotational joint planar mechanism with the Denavit–Hartenberg method. Three different air chamber geometries (rectangular, honeycomb, and half-round) were tested using both finite element simulations and prototypes constructed with Mold Star 15 Slow. The objective was to compare their performance with the reference trajectory. Finally, a test is presented that confirms the actuator's capability to provide flexo-extending to the author's index finger.