The Chemical Circuit

A transistor is a very important electronic device which is used to amplify and switch electronic signals. Semiconductor Chip makers started to use 3D Transistors in 2011 to reduce the size and increase the efficiency of chips. They can pack more 3D transistors into a single chip since it is much more compact than traditional planar transistor.The amount of compactness will not be sufficient for future generations of semiconductor chips and to keep the pace of Moore’s Law. Thus there is a need to shrink these 3D transistors and one possible way to do this is by using nanowires in the transistor design. The area of nanowire based transistor is about half of the traditional planar transistor and it will be lesser if we consider more complicated components.The new design decreased the area required for a Gate All Around transistor by a factor of 2, as they constructed two transistors by using single nanowire. As shown in the above diagram, gates are placed one above the other and are separated using a thin layer of dielectric to isolate them electrically. Unlike other independent double gate transistor designs, the change in voltage on one transistor will not affect the threshold (turn on) voltage of other transistor. Thus either of the gate can control the nanowire current independently.

Ion Transistors for the transport of both positive and negative ions, as well as biomolecules had been previously developed by a group of Organic Electronics research team at Linköping University. Now Tybrandt has now succeed in developing circuits using these Transistors similar to traditional silicon electronics. In essence of this technology we can build computer chips that can directly interface with our body cells.The major advantage of chemical circuit is that the charge carrier consists of chemical substances with various functions and this gives us new opportunities to regulate and control signal paths of Human Body Cells.In a conventional transistor there are three terminals Gate, Source and Drain. When signal is applied to Gate terminal, electrons flow from Source to Drain. Electrons are the charge carrier in conventional transistor, but in the new Ion Transistor the ionic neurotransmitter acetylcholine is the charge carrier. NAND gates and Inverters can be created using these Ion transistors, which means that it can be used to implement any logic function.Magnus Berggren, Professor of Organic Electronics and leader of the research group says that, it can be used to send signals to muscle synapses when our muscle signalling system may not works for some reasons and our chips works with common signalling substances such as acetylcholine.The research in Ion Transistors which can control and transport ions and charged biomolecules was begun before 3 years by Berggren (professor in Organic Electronics at the Department of Science and Technology at Linköping University) and Tybrandt (a doctoral student). Researchers at Karolinska Institute then used this Transistors to control the delivery of the signalling substance acetylcholine to individual cells. It hopes that it can restore the lost movement of paralysed peoples.Mr. Tybrandt in conjunction with Robert Forchheimer (Professor of Information Coding at LiU) has taken the next steps by developing chemical chips which contains logic gates, that allows the construction of all logic functions.