Nanometre-sized printed electronic circuits breakthrough towards flexible electronics
Japanese researchers have developed a technique they say allows large-scale manufacturing of printed electronic circuits only 1 nanometre in size on flexible substrates – a possible breakthrough in the evolution of wearable and bioelectronic devices.
Conventional technologies for semiconductor printing only achieve a resolution of several dozen of mictrometres, which is not enough for manufacturing of minute devices suitable for practical use.
The new technique, developed by a team from the National Institute for Materials Science at Japan’s Research Institute in Tsukuba, improves the resolution to the nanometre level. It enables the creation of rows of nanometre-sized thin-film transistors even on flexible substrates and biological materials, which makes it promising for future manufacturing of medical bioelectronics.
The technique uses a two-step approach. First, hydrophilic and hydrophobic micro-patterns are created on the substrate by irradiating it with parallel vacuum ultraviolet light at a wavelength of 200nm or less. This approach makes it possible to focus the beam on much smaller targets than conventional light sources. Subsequently, metal nanoparticle inks are deposited onto the hydrophilic patterns. The nanoink, containing particles of gold and silver, forms a conductive film on the surface of the substrate. The whole process is carried out at room temperature.
The team say they have tested the semiconductors with satisfying results. In future, the researchers want to create large-area flexible displays and sensors using the technology, which they believe would be suitable for low-cost production.