Self assembly nanochip kits How small can the components be in a microchip? Researchers with an EU-funded project MINT have shrunk the boundaries using a hybrid made of genetic material and conventional integrated circuitry. Digital Economy © Shutterstock Microchips have revolutionised the world of electronics. The most complex integrated circuits, microprocessors, control every appliance from cellular phones to computers. All systems including the internet are dependent on the existence of chips that can house up to one million transistors on a square millimetre. With this level of complexity, it would seem hard for the researcher to make improvements, but an EU-funded project 'Molecular interconnect for nanotechnology' (MINT) has laid a solid foundation for achieving just that. To make this possible, the project scientists have harnessed the unique properties of DNA's single strand partner, ribonucleic acid (RNA). This molecular cornerstone of the genetic code indulges in complementary base pairing. The upshot of this is that the RNA strand can be designed to bond to predictable complementary bits of another molecule, rather like a jigsaw. Big sections of RNA also have a specific folding pattern (the tertiary structure) in which large structures can be deposited. RNA makes molecular self-assembly a reality. The resulting miniaturisation is amazing. Wiring is considerably below 100 nanometres and the attached programmable units are as tiny as 10\;nm in size. At the University of Glasgow, the MINT team has pioneered methods to quantify and control the amount of specially designed oligonucleotides immobilised onto the surface of electrodes. The specificity and degree of immobilisation is assessed using X-ray photoelectron spectroscopy (XPS) to measure the elements present. Mass per unit area is also quantified using a quartz crystal microbalance (QCM). Organic/inorganic electronic devices can be made with a high degree of reproducibility at a competitive cost. The controlled manufacture of nanoscale wires and links between nanoparticles takes this technology one step further.
