A team of researchers and engineers has introduced a novel type of self-adhesive, ultra-thin electronic device, by coupling accurate micro-manufacturing and theoretical modeling, which is capable of measuring information on muscle activity, brain waves, and human heart without employing conductive liquids, glues or massive equipment.
" A newly developed stick-on tattoo with integrated sensor technology, prior to application (from reverse). Credit: J. Rogers, University of Illinois
The scientists have developed a unique set of micro-electronic devices using a technology referred as the epidermal electronic system (EES). Their initial designs included networks of wire filaments, tiny receivers and transmitters, light-emitting diodes, and miniature sensors. Researchers from the Dalian University of Technology in China, the Institute of High Performance Computing in Singapore, Tufts University, Northwestern University, and the University of Illinois at Urbana-Champaign collaborated with each other to develop the EES device.
While current technologies precisely measure muscle activity, brain waves, and heart rate, the EES devices allow the application of sensors that have negligible weight, need negligible power and require no external wires. Since it requires negligible power, power can be drawn from transmitted or stray electromagnetic radiation by means of induction and can harvest energy from tiny solar collectors. The EES designs deliver flat devices with thickness less than 50 ìm, thinner than the human hair diameter, which are incorporated on the polyester backing well-known from the emergence of stick-on tattoos.
These devices are extremely causing close-contact forces known as van der Waals interactions to be prominent in the molecular level adhesions. This causes the electronic tattoos to stay in position for hours by sticking to the skin without the use of any glue. The latest study illustrated device lifetimes up to one day under normal conditions. The scientists are also investigating clinical methods, especially for diseases where size of the sensor is important such as neonatal care and sleep apnea.
Further, scientists expect to integrate microfluidic devices into this technology providing a new opportunity for advanced-functioning skin and electronic bandages, effectively hastening wound or burns healing and other skin disorders.