A twitching, artificial muscle that works on water (60-second science)

I think it’d be great to share what I did in an activity called 60-second science last year in one NUS module.

Here is the paper on Science: Bio-Inspired Polymer Composite Actuator and Generator Driven by Water Gradient

Basically it is a piece of plastic that can absorb water and move by itself.

Whee~~~ (Source: Ars Technica)

During the presentation I said something along these lines:

Try to imagine: The sliced meat you just put into water curls up, rolls and flips by itself. Sounds creepy, right? Now it’s real. Researchers have built a material that is able to move by just getting wet. It consists of strands of a polymer called polypyrrole, or PPy for short, in a rigid network of a different polymer. It looks similar to animal muscle: strands of muscle fibers embedded in a network of collagen. The study was published in the journal Science.

This material absorbed water and the wet side got swollen, and curled towards the dry side. It toppled over, and moved with the help of evaporation of water. It twitched very fast and generated a strong force.

Next they combined it with a material that can generate electricity in response to mechanical change. The product was able to generate up to 1 volt of electricity and to charge up a capacitor in 7 minutes.

This new material can be used to power up our electronic devices, so perhaps next time we are able to charge our hand phones by getting our pockets wet, if you don’t mind the rolling action in the pants.

Here is a video showing it in action:

On hindsight I shouldn’t have said so much jargon (PPE PPy etc) and kept it within 60 seconds. Great learning experience though! 🙂