A key part of the Health Tech wearable revolution is wireless communications. We depend on WiFi and Bluetooth transmissions to connect wearable devices to smartphones, computers, and the Cloud, so that these devices are not tied down by a data cable. To transmit and receive wireless data, you need an antenna. The term may conjure up images of an old television’s “rabbit ears” antenna, or the metal wire sticking up from your car’s hood. But antennas are getting smaller and more efficient; metal strips inside a smartphone case perform the same function, reaching out miles send signals to the nearest cell tower.
Researchers at Drexel University have been working to develop new antenna technology that can be spray-painted onto a surface. Traditional designs use solid metal strips made from copper or gold. Some newer devices rely on nanomaterials such as graphene that can be complex to fabricate. The Drexel designs use a new material called MXene, a titanium carbide material that is water soluble. Adding water creates a simple ink that can be sprayed onto a surface where the particles self-assemble into an extremely thin conductive layer. The Drexel team created antennas on substrates ranging from simple paper to thin plastic sheets. The researchers have found that a layer just one-thousandth of the thickness of a sheet of paper is sufficient for a working antenna, even though the layer is nearly transparent. In tests, the MXene sprayed-on antennas out-performed the much thicker metal antennas, as well as the very thin nanoparticle materials.
The light weight, thin profile, and high conductivity of this technology could make wireless wearables smaller and more efficient at transmitting wireless data to other devices.