ETH-Zurich researchers have developed an economic, fast and reproducible method for printing micro- and nanoscale (<100 nm) structures in a manner similar to an ink-jet printer printing art.

The trick: ultrafine particles are transferred onto a surface from a capillary with the aid of an electrical field. Depending on how long material accumulates at the same spot, the structure can be a dot or nano-tower, or even an arch.

Surfaces modified with nano-structures can absorb, concentrate and transmit light instead of reflecting it.

Applications

• Increased efficiency of thin-film solar cells by capturing the light and channeling it directly towards the active layer, for instance, instead of reflectng part of the light and letting another part escape unused.
• Camouflage suits
• New kinds of faster, more selective and highly sensitive detectors and sensors might be feasible.
• Special light microscopes in which light nanoantennas trigger fluorescence, enabling individual molecules to be observed.
• Wherever material needs to be applied on a nanoscale in a targeted fashion — a CPU printed on the spot, for example.

Advantages

• Structures can be applied to different surfaces in a quick and reproducible manner.
• Fast because the printer can be programmed in such a way that material is applied precisely where it is needed.
• Removal and waste of excess material no longer required.
• Less expensive — no large-scale facilities, high calssification cleanrooms, exceedingly high temperatures or special pressure ratios, and laborious and time-consuming vacuum steps.
• Throughput and size of the printed surfaces may be increased considerably during industrial production.
• Prototyping at the smallest scale could be performed fast and affordably.

The researchers next plan to develop a print head containing several individually addressable capillaries to increase throughput and enable stacking layers of different materials.