New lithography technique ‘allows for low-cost creation of nanostructures’

Researchers have created a promising new way of using nanoscale spheres to create 3D structures with biomedical, electronic and photonic applications.

Developed by engineers at the North Carolina State University, the new method involves placing nanoscale polystyrene spheres on the surface of a photosensitive film. These nanospheres are transparent, but bend and scatter the light that passes through them in predictable ways.

Unlike traditional methods – which use a variety of techniques to focus light on a photosensitive film to create 2D patterns – there is no need to use specialised lenses, electron beams, lasers or mechanical probes, all of which are expensive.

The team controlled the nanolithography by altering the size of the nanosphere, the duration of light exposures, and the angle, wavelength and polarisation of light. It allowed 3D structures to be created in one piece, rather than making multiple layers of 2D patterns.

Study author Dr Chih-Hao Chang, an assistant professor of mechanical and aerospace engineering, said: "Our approach reduces the cost of nanolithography to the point where it could be done in your garage."

Techniques such as this will be invaluable in the future creation of nanoscale electrical devices, data storage drives, sensors and drug delivery systems.