Growing microchips using proteins from living cells

Researchers at the University of Arizona are exploring ways to ‘grow’ microchips using proteins from living cells.

Microchips currently are made by lithography, etching and soldering. The new biological interconnects would reportedly bypass these processes with long strings of proteins called microtubules (MT).

MTs would connect transistors and other devices in microchips by growing between the device junctions. They’re solder-free, don’t involve lithography or etching and are highly uniform. Once the proteins connect devices, they will be coated with metal and turned into microscopic wires.

MTs are common in nature. They help cells carry out mitosis (cell division) and have diameters of about 24 nanometers. MTs can also grow to several microns in length, which makes them ideal for fabricating incredibly tiny wires.

These sizes are difficult to achieve with current lithographic processes and today’s microchips have connector widths that are two to three times wider than metalised MT diameters.

Because they are uniform in size, have very little process variation and will self-assemble, MTs can be used in low-power circuits to lower energy demands 10 to 100 times below those of conventional circuitry.

When MTs are grown on a microchip, they will ‘know’ where to make the proper connections because their ends have different polarities. With the proper chemistry, an MT’s polarity can be exploited to cause the proper end to be attracted to the proper connector.

‘I can envision in the long term the idea of using biomolecules as building blocks where more traditional materials are used in many applications now,’ said Materials Science and Engineering Professor Pierre Deymier.

He added: ‘This is a whole new technology at the interface of biology and engineering, and I can see us creating a new paradigm in device making and a new technology for engineering. It has great potential.’