Researchers in Taiwan were trying to build an artificial muscle, when suddenly they realized: “Wait a second, why don’t we just use gold-plated onion skin?” Best. Eureka. Moment. Ever.
OK, it probably didn’t happen quite like that. But they were trying to create an artificial muscle, and they did find that onion skin proved to be a pretty decent alternative — and an eco-friendly one at that. Here’s more from The Verge:
The muscle is built on the epidermis of the onion, the filmy layer underneath the outer shell. Like real muscles, that film is both stretchy and responsive to electricity, thanks to the single-layered lattice structure of its cells. Still, getting the film to work as a muscle took a lot of preparation. The team freeze-dried the skin to remove internal water and dipped it in dilute sulfuric acid to make the skin more elastic. Then the onion skin was dipped in two layers of gold and an electrode was attached.
Scientists have been trying to build artificial muscles for a while, but — surprise! — living tissue is complicated and awesome and really difficult to replicate (kudos, evolution). More specifically, it’s hard to fabricate a soft, robotic muscle that can both bend and contract/elongate at the same time.
The researchers in Taiwan were trying to do this using polymers, when they realized that nature already provided the very kind of material they were trying to create. They reported their discovery in the journal Applied Physics Letters:
The plant epidermal cells are cheap and easy to obtain, at no cost to the environment. Due to the diversity of plants and their cell structures, discovering the use of natural structures in engineering is of interest.
To test their onion muscle, the researchers put two together to form a pair of tweezers and then used those gold-plated onion tweezers to pick up a cotton ball, making us all regret our career choices.
This research is all part of a larger field of research called soft robotics, which is exactly what it sounds like. Scientists in the field want to build robots that are more lifelike. That is, soft and squishy — you know, like us. What could go wrong? Seriously, though, soft hardware (software? squishware?) could do great things for the world of medical implants.
If you want to see some early-stage soft robots, check out this creepy little sucker from Harvard:
Or this disturbing octopus arm from Italy: