About
Most robots exist with the goal of a specific human-centered mission - optimized for sensing something in their environments and sending back data to human sponsors. Soft robots - shaped from compliant materials and powered by air - can take on elegant forms, move about gracefully, and offer minimally invasive interactions with their environments due to their soft bodies. Taking these character traits to their fullest extents, Carolyn Nguyen and I designed a soft creature evoking the nature of a tumbleweed. ‘Tumbleweed,’ as a creature, is nomadic, non-invasive, and more often than not ‘going with the flow.’ We envision Tumbleweed exploring expanses in a non-invasive way and writing back notes about their exploration to us.
Tools/Skills: Design concept, silicone mold development in CAD + 3D printing, Arduino programming with pumps + air valves, poster sketches
Concept Shaping
We took structural inspiration from existing soft robotics experiments in university research labs, and design inspiration from exploratory rovers, nomadic wanderers, and whimsical kinetic sculptures.
Different modes of motion, or animations, helped to inject some personality into our soft robot creature and demonstrate its current state of being. Below is an illustration of these four modes that we designed:
Silicone Mold Manufacturing
We utilized some of existing soft robotics molds as starting points and duplicated and scaled them in order to make a series of inflatable columns. The following images show some custom mold and assembly jigs, silicone casting revisions, and a series of experiments that led us to our final casting form.
Electronics Manufacturing
The electronics control portion of this project was my main focus. Programmable air pumps and soleniod valves were used to control the inflation/deflation of each of Tumbleweed’s columns. By programming alternating sequences of inflating or deflating, we were able to produce the motion and animations we envisioned. For this course project, we used a series of off-the-shelf transistor breakout boards and H-bridges that were available to us. In a more polished iteration, the design could be packaged much more elegantly into a single controller board.