Scientists from Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory have made flexible, transparent electrical conductors with record-high performance for use in solar cells, displays, and other devices by spreading polymers on a clear surface with a tiny blade, like a knife spreading butter on toast.

The solution shearing apparatus. (SLAC National Accelerator Laboratory)

A matchbook-sized silicon blade spread a thin layer of PEDOT:PSS, a conductive blend of two polymers that turns transparent as it dries, on various surfaces at speeds up to 6 meters per minute. By varying the speed and adjusting the temperature of this process, the researchers were able to produce see-through films of various thickness and conductivity, and also get the PEDOT and PSS polymers to separate into layers, which increased the film’s conductivity even more.