An arm rest must support loads while maintaining its structure. The common static design of an arm rest can increase collision hazards, especially for small children whose heads are near its edge. I designed position holding pneumatic actuators and a reconfigurable structure that can support weight while in use and stow away while not in use or during collisions. This structure is actuated pneumatically and forms a rigid shape with smooth edges when deployed. 

To characterize the torque produced by a single pneumatically actuated hinge, I created a model based on first principles analysis and geometric design parameters. Experimental validation confirms that this model can predict the trends and overall shape of a torque vs angle curve for hinges of different design parameters. Based on results from my analytical model, I designed and fabricated a prototype for a reconfigurable armrest structure.