A simple, scalable and low cost transparent display system has been showcased by MIT researchers. The approach uses nanoparticles embedded in a transparent plastic based material. The particles can be tuned to scatter specific wavelengths, or colours, or light while others pass through it. This enables the plastic to remain transparent while the selected colour is visible on the display.
The nanoparticle infused transparent material can be bonded onto other materials including, as MIT note in an application example, glass to produce a windscreen that shows navigation or dashboard information.
Furthermore the MIT system offers a wide viewing angle that exceeds that currently offered by “heads-up†display solutions that use a mirror or beam-splitter to project an image directly to the user’s eyes.
The system is described in a paper published this month in the journal Nature Communications, co-authored by MIT professors Marin Soljacic and John Joannopoulos, graduate student Chia Wei Hsu, and four others.
To demonstrate the system, the team projected a blue image in front of a scene containing cups of several colours, all of which can clearly be seen through the projected image. While the team’s demonstration used silver nanoparticles — each about 60 nanometers across — that produce a blue image, they say it should be possible to create full-colour display images using the same technique.
Three colours (red, green, and blue) are enough to produce what we perceive as full-colour, and each of the three colours would still show only a very narrow spectral band, allowing all other hues to pass through freely.
Soljacic said: “The glass will look almost perfectly transparent because most light is not of that precise wavelength that the nanoparticles are designed to scatter. That scattering allows the projected image to be seen in much the same way that smoke in the air can reveal the presence of a laser beam passing through it.â€
MIT suggests that the display could be used on store windows or windscreen displays for drivers or pilots. The work, which also included MIT graduate student Bo Zhen, recent PhD recipient Wenjun Qiu, MIT affiliate Ofer Shapira, and Brendan Lacey of the U.S. Army Edgewood Chemical Biological Center, was supported by the Army Research Office and the National Science Foundation.