Session: MR-07-04 - Novel Mechanisms, Robots, and Applications

Paper Number: 91266

91266 - Experimental Characterization and Modeling of a Unit Soft Air Bladder 

The goal of this study was to understand the behavior of a single soft air bladder constructed from nylon-coated thermoplastic polyurethane (TPU) using a CNC heat-sealing device.

More specifically, the aim was to examine how external loads and internal pressures of the bladder, can vary as a function of applied compressive displacement, and initial inflation pressure. Additionally, we aimed to explore how various parameters such as geometry (size, shape) and fabrication method (3-sided vs. 4-sided seal, location of the air fitting on the bladder) would affect the performance of being able to withstand high external loads and internal pressures.  To do so, we conducted a series of force-displacement compressive experiments using an Instron machine. Our experimental results suggest that larger initial inflation pressures can withstand higher forces and internal pressures. We also found that bladder size and shapes affect bladder behavior. Circular bladders and smaller-sized bladders can withstand lesser forces and internal pressures as compared to square bladders and large bladders. Based on the experiments results, a set of design guidelines that help identify the bladder starting conditions needed to meet requirements were also proposed to help engineers design bladder actuators for various soft-robotics applications. A simple analytical model for circular bladders was also developed to predict bladder inflation height as a function of initial inflation pressure and externally applied load and was validated against our experimental results.

Presenting Author: Sandra Edward University of Illinois, Urbana-Champaign

Presenting Author Biography: Sandra Edward is a first-year Ph.D. student at the University of Illinois Urbana Champaign in Mechanical Engineering. She recieved her M.Sc. in Mechanical Engineering at the University of Michigan Ann Arbor, and her B.Sc. in Mechanical Engineering at the University of Kentucky. Her research has focused on soft pneumatic actuators and their applications.

Authors:

Sandra Edward University of Illinois, Urbana-Champaign
Mahshid Mansouri University of Illinois, Urbana-Champaign
Elizabeth T. Hsiao-Wecksler University of Illinois at Urbana-Champaign
Girish Krishnan University of Illinois Urbana-Champaign