Using industry-standard manufacturing technology, researchers have integrated ultrathin and stretchable silicon-based electronics, sensors and actuators on an artificial skin that can be worn on the tip of your fingers. The result is an artificial finger cuff that could be used to produce the ultimate hi-tech surgeon's glove, capable of sensing the electrical properties of tissue, removing tissue precisely using local ablation, or even performing ultrasound imaging with a simple touch.
Electrotactile stimulation is a technology allowing information to be detected by a sensor and then presented to the skin as an artificial sensation of touch. This is usually done via a specific vibrational pattern or tingling sensation generated by a small electrical current. The technology was first explored in the fifties to develop programmable Braille readers and is now finding new applications – even helping the visually impaired to "see" with their tongue.
The device developed by researchers from the University of Illinois at Urbana-Champaign, Northwestern University and Dalian University of Technology improves on previous designs in two key areas. Firstly, it isn't a bulky gizmo, but rather fits in its entirety on both sides of a flexible, elastic finger cuff. Secondly, these "artificial fingertips" can not only relay information (temperature, conductivity, and so on) to the skin, but could also – thanks to actuators positioned on the outside of the cuff – perform surgery by heat-induced local ablation, or even obtain ultrasound imagery of the tissue "at hand."
Building the cuff is a relatively straightforward process: a flexible polymer is repeatedly poured onto a model finger until it achieves the desired thickness. The result is an elastic sheet in the shape of a fingertip that is then heated at 70° C (158° F) for two hours to form a free-standing structure. The required circuitry is then delivered onto the surface of the artificial skin via transfer printing.
A prototype "electronic skin" was designed with the simple goal of measuring the stresses and strains at the fingertip by reporting the change in capacitance of tiny microelectrodes embedded in the device. But one of the strengths of this design is that it can be easily adapted to suit different functions. For instance, it could be easily fitted with additional sensors for measuring motion and temperature, among other things.
Future applications might include robots that can interact with their surroundings with a much softer touch, even performing surgery. For now, however, the researchers are interested in seeing whether the artificial skin they have developed could be wrapped around other parts of the body. For instance, a skin wrapping the entire surface of the heart with custom sensors and actuators would provide advanced tools to diagnose and treat cardiac arrhythmia. The first step towards this goal, however, is to find a way to provide the skin with wireless power and data transfer capabilities.
The research was detailed in a paper recently published in the journal Nanotechnology.
Source: Institute of Physics
