OLD-fashioned “spring” thermometers are notoriously inaccurate. So would a nanoscale version be any better?
Yes, according to Nicholas Kotov at the University of Michigan, Ann Arbor. His team has built thermometers just 30 nanometres wide that function much like their larger cousins and can indicate temperatures to within 3 °C over the range 20 °C to 80 °C. Spring thermometers, which rely on a coil made up of two different metals that winds and unwinds as the temperature changes, can be out by 10 °C.
In the nanoscale version heat-sensitive springs composed of polyethylene glycol chains are attached at one…
