Imagine a bandage that could tell healthcare workers at a glance what was going on underneath. Does a dressing need to be changed? Is there bacterial growth that indicates an infection? Is the temperature of the skin hotter or colder than normal, which could indicate problems with circulation and healing? This just one possible application for a new display developed jointly by Panasonic and researchers from Chiba University in Japan. In a paper presented at the Society for Information Display’s Display Week 2015, they revealed details about a bi-stable display that is not only flexible, but stretchable.
The display is based on electrophoretic technology, which may be familiar from its use in some ebook readers such as the Amazon Kindle Paperwhite. This is a reflective technology that does not emit its own light. Also, it consumes almost no power until the image changes, which means that it uses much less power than emissive displays such as OLED or LCD. The Panasonic and Chiba researchers created a panel using flexible plastic substrates instead of the usual glass substrates. Traditional transparent electrode layers are made with a thin film of ITO (Indium Tin Oxide), but this is a brittle material that fails quickly when stretched or bent. Instead, the researchers used carbon nanotubes (CNT) as a transparent conductive layer.
The result is a display that had image quality equivalent to that of a panel made with rigid glass and ITO conductor layers, even when stretched by about 10%. The result is a low-power and lightweight display that can easily conform to typical body shapes, making it useful as a visual display interface for some wearable Health Tech applications.
