We’re already into the second week of the new year and we’re excited to introduce you to our next curator, PhD candidate Caleb Christianson (@ClbChrstnsn). Caleb is a fifth-year PhD candidate in the NanoEngineering Department at UC San Diego. Caleb’s research is on developing artificial muscles and sensors for bioinspired, soft robotics. Now, these are not your Transformer-type robotics, awesome though they are. Soft robotics is about inventing new
materials to create robotic devices that mimic humans and animals – polymer muscles, for instance, bendable electrodes, robotic arms that can perform surgery at a distance. Electronic skins that behave like human skin but aren’t made from cells. Artificial limbs that bend and stretch like human limbs. This means having to come up with new materials or modifying existing ones so they behave like human tissues, then making the mechanical device and so on. It’s fascinating work that means you have to understand many disciplines from biomechanics (the mechanics behind limbs, walking etc), materials science and engineering.
Caleb has published on topics including uncooled infrared detectors, superconductors, micro- and nano-robotics for defense and biomedical applications, and bioinspired soft robotics. He’s interned at NASA Jet Propulsion Laboratory, Science Applications International Corporation (SAIC), and four startups. Caleb spoke to us about how he ended up in nanoengineering and robotics.
From third grade on, I was homeschooled and lived in the country in a town of 233 people. This provided me with ample time to explore nature through walks on our farm as well as field trips to the local conservation center. I was also a huge fan of watching Bill Nye the Science Guy on PBS. In high school, my favorite class was physics as I was intrigued by the idea of a discipline that could describe the mechanics behind everything around us. I then went on to study engineering physics at the University of Kansas, which combined the practicality of an engineering education with an exploration of the underlying physics that govern engineering design.
I was a huge computer nerd in high school: I loved building, breaking, and fixing computers for myself, friends, and family. I was also very interested in learning how to use technology to help people and support my family. It seemed to me at the time that a lot of my peers were also interested in working in computers, so I thought it would be interesting and useful to start studying something a little farther out. During that time I was reading books by K. Eric Drexler, Ray Kurzweil, and Richard Feynman, and I was fascinated by nanotechnology and how we could develop technology at the nanoscale to improve the quality of life for people. This led to me working in several research labs working in nanotechnology research, completing my M.S. in nanoengineering, and pursuing my Ph.D. in nanoengineering.
Now I am applying my experience in materials, engineering, and physics to developing artificial muscles and sensors for bioinspired soft robotics.
My research is on developing artificial muscles and sensors for bioinspired soft robotics. Most recently, I worked on an eel-inspired robot that swam silently, was transparent, and fluoresced. Soft robots are robots that are made from polymers or rubber-like materials instead of rigid materials like metal or plastic. This allows soft robots to better adapt to their environments and be safer when interacting with people and delicate objects. The artificial muscles that I work with are called dielectric elastomer actuators and are essentially stretchable capacitors. If you have a thin sheet of rubber and you have two parallel, conductive plates on either side of the sheet, and you apply a high enough voltage to the conductive plates, the charges will accumulate on either side of the plates and compress the rubber. If we carefully design these actuators into soft robots, then we can use electricity to make the robots move.
Three key benefits of soft robots are that 1) their deformable bodies enable them to adapt to grasping a wider variety of objects than more typical rigid grippers, 2) they are more adaptable to moving through uncertain terrains and obstacles, and 3) their soft bodies are safer for human (or animal)-robot interaction than robots comprised of fast-moving, rigid components.
In his spare time, Caleb TAs for a graduate robotics class. His favourite hobbies include surfing and mixing sound for his church and for a local band.
And the ideal day off?
Sleep in, have a nice walk on the beach with my wife and our dog, surf a little, grab some tacos and a beer while watching the surf, take a nap on the beach, read, listen to some music, grill some dinner while enjoying a glass of scotch, eat dinner while watching a movie on the couch, and then read until my eyes won’t stay open anymore.