Transistors – The Invention That Changed The World
Engineers have developed transistors entirely composed of linen filaments covered with carbon nanotubes, which can be used to create any logic and integrated circuits and entire electronic devices..
The field of flexible electronics is rapidly evolving, and in most cases elasticity is achieved through corrugating metals and semiconductors or through the use of conductive polymers. However, a team of scientists from Tufts University has found an alternative solution to get rid of the rigid components and create fully bendable multiplexed devices..
During the study, engineers created a simple small integrated circuit called a multiplexer and connected it to a sensor array of filaments capable of detecting sodium and ammonium ions. – important biomarkers of cardiovascular health, liver and kidney function.
To make a new type of transistor, the scientists coated a linen filament with carbon nanotubes, which create a semiconductor surface through which electrons can travel. Attached to the thread are two thin gold wires – «a source» electrons and «runoff», where do they go. A third wire, called a gate, is attached to the material surrounding the filament so that small voltage changes increase the amount of current flowing between the source and drain – the basic principle of a transistor..
An important innovation in this research is the use of an electrolyte-filled gel as the material surrounding the filament and connected to the gate wire. In this case, the gel consists of silica nanoparticles, which independently form a mesh structure. The electrolyte gel can be easily applied to the thread by dipping or quickly spreading. Unlike solid-state oxides or polymers used as a gate material in classical transistors, an ionogel is elastic when stretched or bent..
The image shows the manufacturing sequence of transistors..
Electronic devices created entirely from fine threads can be woven into fabric, worn on the skin, or even surgically implanted for diagnostic monitoring.
Recall that in May, engineers managed to create the world’s first all-optical transistor with a switching frequency of several terahertz, which is capable of operating at room temperature..
text: Ilya Bauer, photo: Tufts University