In the most advanced prosthetics–such as this crazy mind-controlled robotic arm–electronic hardware interfaces directly with nerves and muscles in the human body. But getting living tissue to play nice with a circuit board is anything but easy, for a number of reasons. One fundamental obstacle you may not have considered: electronics send signals via negatively charged electrons, whereas many of the communications carried out in living tissues take place through the movement of positively-charged particles, such as calcium and potassium ions.
Now, though, scientists have discovered a new feature of a protein called reflectin, found in a group of animals called pencil squid. It turns out reflectin conducts protons and may be able to bridge the communication divide between cells and biomedical implants. Genetic Engineering and Biotechnology News explains:
[The team] began studying reflectin to discern how it enables the squid to change color and reflect light. They produced the squid protein in common bacteria and used it to make thin films on a silicon substrate. Via metal electrodes that contacted the film, the researchers observed the relationship between current and voltage under various conditions. Reflectin transported protons, they found, nearly as effectively as many of the best artificial materials.
It’s ability to move around these positive charges and it’s “tunability,” or versatile nature, could be used to build implants and prosthetics that can more easily communicate with the human body. The fact that it is biological and flexible means that it may be better than existing materials for integrating into the human body, and with a lower chance of being rejected, the researchers (from the University of California, Irvine) said. And since it is a protein, it could be modified in other desirable ways, such as possibly being able to biodegrade after it is done serving a useful purpose, which could help patients avoid additional surgeries.
The squid protein reflectin is also being investigated to make better camouflage, thanks to its interesting optical qualities.