But what if size matters?
Some recent attempts at creating new and much smaller semiconductors were aimed at making wearables more comfortable or fit better into narrow spaces. These efforts have been based on molecular engineering, using the biological building block Deoxyribonucleic acid (DNA). DNA is a double-stranded, helical macromolecule which usual function is to encode the genetic information of an organism; these properties have been exploited to manipulate DNA’s ability to fold into 2D and 3D-shapes in a nanoscale range in the so-called DNA origami technique.
DNA as building blocks to can allow for new industrial design
The idea of using DNA as a construction material is perhaps not that new as the principle was already established in the 1980s. However, the technology has evolved significantly since then. Currently, scientists are trying to use DNA’s very small size, base-pairing capabilities and its inherent ability to self-assemble to create nanoscale structures for electronics, resulting in drastically reduced component sizes. The smallest features on chips currently produced are roughly 10 times larger than the diameter of single-stranded DNA – just 1.2 nm. DNA as such does not conduct electricity very well but metal-containing DNA origami structures do.
The future might be in interdisciplinary engineering
In essence, DNA structures can serve as a 3D structural scaffold which supports construction of an integrated circuit on them, thus forming a molecular semiconductor. In collaboration with Robert C Davis and John N Harb at Brigham Young University, Woolley’s team at Brigham Young University published the build of a 3D tube-shaped DNA origami structure that sticks up from common base substrates (e.g. silicon) and can form the bottom layer of a chip. They describe their ultimate goal as attaching gold nanoparticles to tube-like origami structures and to place them at particular sites on a substrate. Linking these gold nanoparticles with semiconductor nanowires would ultimately form a circuit.
Conventional chip fabrication becomes extremely costly when it comes to very small chip dimensions. A technology that is based on self-assembling DNA carries great potential for cost savings. Yet we are only witnessing the onset of interdisciplinary engineering in the 21st century.