Biomechatronics Lab
I began to research for the Biomechatronics Lab in Media Lab during the IAP of my freshman year. My project involved creating a soft robotic pneumatic system that could provide pressure feedback to lower extremity amputees. The system involved air bladders that are placed in the amputee’s prosthetic foot. When the individual applies force, the pressure exerted translates to the extent actuators placed on the individual’s feeling thigh inflates. This offers them pressure feedback while walking, allowing for increased sensory feedback to improve the rehabilitation process.
Build
We began experimenting with using plastic bags as the air bladders. We tried several different kinds of materials, to find which would be most durable. For the actuators, I designed several kinds of molds in Onshape inspired by my accordion-like actuators. After these molds were 3D printed, I fabricated the soft robotics actuators using MoldStar silicone solution. We went through several iterations of the actuator, modifying the width and number of bellows, until we found a design that performed well. We also began looking into using the Formlabs SLA printers to print the actuators to speed up the manual process of fabricating them.
Electronics
For the force sensors, I experimented with FSR (Force Sensitive Resistors) sensors and pressure transducers. We attempted to place a FSR sensor into an air bladder, though were unable to receive accurate pressure readings as the bag was compressed. We continued to look into other methods to tackle this problem. We found force receptive shoe soles and decided to look into them as an alternate solution.
Software
I wrote scripts that synced with an Arduino and were able to generate graphs of pressure and force based on buttons clicked. I also interfaced with the sensors using C++.
Results
Although I wasn’t able to stay with the project through to completion, the experience significantly strengthened my Onshape CAD skills and allowed me to get the project successfully off the ground.