The Sept. 20, 2011 news item (Proton-based transistor could let machines communicate with living things) on Nanowerk features a rather interesting development,
Human devices, from light bulbs to iPods, send information using electrons. Human bodies and all other living things, on the other hand, send signals and perform work using ions or protons.
Materials scientists at the University of Washington have built a novel transistor that uses protons, creating a key piece for devices that can communicate directly with living things.
Here’s a diagram from the University of Washington Sept. 20, 2011 article about the proton transistor by Hannah Hickey,
Here’s a little more about the proton transistor (from the Hickey article),
In the body, protons activate “on” and “off” switches and are key players in biological energy transfer. Ions open and close channels in the cell membrane to pump things in and out of the cell. Animals including humans use ions to flex their muscles and transmit brain signals. A machine that was compatible with a living system in this way could, in the short term, monitor such processes. Someday it could generate proton currents to control certain functions directly.
A first step toward this type of control is a transistor that can send pulses of proton current. The prototype device is a field-effect transistor, a basic type of transistor that includes a gate, a drain and a source terminal for the current. The UW prototype is the first such device to use protons. It measures about 5 microns wide, roughly a twentieth the width of a human hair.
As for the device (from the Hickey article),
The device uses a modified form of the compound chitosan originally extracted from squid pen, a structure that survives from when squids had shells. The material is compatible with living things, is easily manufactured, and can be recycled from crab shells and squid pen discarded by the food industry.
There is a minor Canadian connection,
Computer models of charge transport developed by co-authors M.P. Anantram, a UW professor of electrical engineering, and Anita Fadavi Roudsari at Canada’s University of Waterloo, were a good match for the experimental results.
If I understand this correctly, the computer models were confirmed by the experimental results, which means the computer models can be used (to augment the use of expensive experiments) with a fair degree of confidence.
I am finding this integration of electronics into the body both fascinating and disturbing as per my paper, Whose electric brain? More about that when I have more time.