Exoskeletons: The Future Of Assistive Care

Exoskeletons: The Future of Assistive Care Twang. A sharp strip of metal flew past my face, narrowly glancing off of my safety glasses and ricocheting off the wall of the Energy Systems lab. I had spent the last twenty minutes trying to build an arm brace, but the aluminum was just not cooperating. I am building an upper body exoskeleton to aid the old and infirm. Or I would be if I could get this arm brace complete. I threw down my tools and walked out of the lab, half out of exasperation and half out of fear of bodily injury. I decided to put off the actual construction of my exoskeleton for another day, there was still a lot of work to be done. I am researching the types of driving mechanisms (technologies used to control the movement
Most of the technology I’m working with is pretty simple by itself. I’m using a DC motor cannibalized from an electric car window. A DC motor, or direct current motor, is a common electric motor that is run off of direct (positive and negative) current. It helps to think about batteries which have a positive and negative end, not the wall outlet. DC motors can be found in objects such as cordless drills or battery operated remote control cars. I will also be testing shape memory alloy (muscle wire) and a pneumatic system. Muscle wire and pneumatics are a bit more complex. Muscle wire is a thin wire usually made of a nickel-titanium alloy that morphs into a preprogrammed shape when introduced to heat or electricity. The pneumatic system I’m using uses pressurized air to push a piston out of an airtight chamber. Exoskeletons have long been products of science fiction, but recently researchers have seen the potential of exoskeletons as rehabilitation or assistive devices for weak patients. My exoskeleton, in addition to helping disabled patients, will serve as a testbed for several technologies, if I can actually get it built. I’m trying
Researchers Brown, Tsagarakis, and Caldwell have looked into several types of movement systems for exoskeletons. The researchers gave the pros and cons for each technique (motors, hydraulics, muscle wire, etc.) and the researchers looked at past successful examples of exoskeletons (Brown, Tsagarakis, & Caldwell, 2003). The tried and true DC motor has had the most the most prior success, but the researchers found potential for the use of pneumatics and muscle wire. In order to transfer the movement from the muscle wire to the flexion or extension of the arm, researchers needed a way to mimic human tendons. Researchers Deng, Wang, He, and Xue looked into the efficacy of a cable drive. The cables act the same way as our tendons, when the muscle wire contracts it pulls on the cable lifting or lowering the robotic arm at the elbow joint (Deng, Wang, & Xue,