TU Delft university stumbles upon tech for energy efficient mechanical pixels

Santiago Cartamil-Bueno, a PhD student at the TU Delft university in Netherlands was exploring new devices to be used as sensors. For this purpose, a thin sheet of silicon was peppered with tiny holes 13 micrometres wide, and covered with two layers of graphene. Due to small pressure differences in the pits, the graphene layer would randomly start changing colour. “Seeing the colours under a microscope, I realised that the devices were not homogeneous, which is bad if you are trying to create a sensor,” Cartamil-Bueno said. The devices may not be of much use as sensors, but the changing colours opened up new possibilities. The research into the use of thin graphene layers as mechanical pixels was lead by Dr. Samer Houri. “We observed Newton rings and noticed their colour changing over time,” Houri said. The pits in the silicon layer were making the graphene layer over the pits behave like balloons. If the graphene was deflated, it appeared blue, if inflated, it appeared red.

The researchers found that they could control the colour continuously by controlling the amount of pressure in the pits. The technology can potentially be used in flexible displays for ebook readers and smartwatches. The energy requirements for such screens would be low, as the pixels are physical and not digital. The researchers are exploring means of controlling the pixels on the screen electrically. Such a screen is called an Interferometric Modulator Display, or an IMOD for short. “An IMOD could drastically improve the device performance – power consumption, pixel response time, failure rates, etc.–  while enabling electrical integration and even flexible devices” Cartamil-Bueno says. The researchers hope to have a prototype ready for presentation at the 2017 Mobile World Conference in Barcelona.