Scientists at the University of Washington have published details of a new protonic transistor which can be used to directly interface biological and electronic systems. The device, which was described this week in the journal Nature Communications, is a protonic equivalent of the electronic field effect transistor (FET).
Transistors are one of the fundamental building blocks which make up all of our electronic devices and the FET is one form of transistor. At a basic level, electronic transistors allow an applied voltage to control the flow of electrons (electric current) through them and can be configured as switching devices to turn the current on and off. The protonic transistor exhibits similar characteristics but controls the flow of protons (protonic current). The significance of this is that an applied voltage can now be used to control proton flow and to send pulses of protonic current, which could eventually be used for interfacing biological and electronic systems at a very low level.
The protonic FET is partially made of a compound extracted from squid called chitosan, which is biodegradable, bio-compatible and non-toxic. A current limitation of the device for human use is the presence of a silicon substrate necessary for the operation of the device, which renders it bio-incompatible. However, use of an alternative semi-conductor substrate in the future could remedy this problem.
This is quite a development from a medical engineering point of view and, while commercial applications of this technology for clinical (or cyborg) use are many years ahead, this technology could possibly enable a new family of hybrid electronic/biological devices.
Abstract in Nature Communications: A polysaccharide bioprotonic field-effect transistor