Yei Hwan Jung/Universidade de Wisconsin-MadisonResin-coated cellulose nanofibril chip, resting on a leafYei Hwan Jung/Universidade de Wisconsin-Madison
A microchip made of cellulose – the fiber found in wood – designed at the University of Wisconsin-Madison in the United States has been presented by researchers as a solution for a growing problem: the disposal of obsolete integrated circuits. Their research was reported in Nature Communications (May 26, 2015). A conventional chip is mostly composed of a supporting layer that houses the processor, which is responsible for making a computer work. In a partnership with the U.S. Department of Agriculture, the researchers at Wisconsin-Madison University replaced that normally metallic layer with cellulose fibers just nanometers thick, known as cellulose nanofibrils (CNF). Since wood can contract or expand according to the level of humidity in the air, they coated the natural polymer with epoxy resin, producing a more water-resistant material. By proposing this solution, the researchers hope to replace most of the existing processors and microchips with biodegradable – or even reusable – material. To demonstrate the technique’s feasibility, they used a wooden substrate to create a microchip measuring 5 by 6 millimeters, with 1,500 gallium arsenide transistors, the standard material used by the electronics industry for manufacturing integrated circuits. According to the researchers, the performance of the prototype was similar to that of the integrated circuits used today.
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