BME Master's Defense Announcement for Shaiv Mehra (B. Duerstock, advisor)

Everyone is invited to attend the public presentation beginning at 1:30 PM EST.

Title: Design and Evaluation of Compliant Grippers for Upper Limb Assistive Robotics

Date: July 17^th, 2025

Time: 1:30 pm

Location: MJIS 2001 and Zoom: https://purdue-edu.zoom.us/j/91670534643?pwd=l0DqxYa7LtbztVmI4qBlIhR7bqUk3i.1

Committee Members: Dr. Bradley Duerstock, Dr. Juan Wachs, Dr. Yu She

Abstract:

Upper limb disabilities, particularly hand paralysis, significantly impair a person’s ability to grasp objects, limiting their performance of activities of daily living such as eating, grooming, and handling household items. This loss of function often leads to reduced independence and diminished quality of life. Neurological conditions such as stroke, tetraplegia, and progressive multiple sclerosis often result in such impairments.  Leading commercial assistive robotic grippers are typically rigid and rely solely on human visual judgment for grasping. Especially for users with reduced cognitive or sensory function, this hinders manipulating delicate or irregularly shaped objects, often leading to drops or breakage. To address this, compliant grippers are being explored for their adaptability to grip these objects, reducing failures during manipulation. Although the Fin Ray structure is widely considered optimal for compliant grippers, flexible 3D-printing filaments allow typically stronger infill structures to be compliant and easily manufacturable. In the first study, a new assessment was developed that scores compliant grippers based on force output and contact surface area. Their balance is important as the gripper must distribute pressure along the object’s surface while still applying the force necessary to lift it. In a comparison of eighteen grippers varied by mass and infill geometry, another structure outperformed the Fin Ray while requiring less material to manufacture. In a subsequent human study, the developed compliant gripper outperformed a rigid gripper in visually judged grasping of everyday test objects of variable shapes and fragilities. Qualitative testing also supported the adoption of compliant grippers in assistive robotics.