Jellyfish Inspire Researchers to Create a Self-Healing, Electronic Gel for CircuitsApril 06, 2020 by Tyler Charboneau
How might this new membrane improve touchscreen designs and transparent PCBs?
Scientists at the National University of Singapore (NUS) have developed a transparent electronic skin, optimized for aquatic applications. The researchers say this new membrane is also stretchable, self-healing, and responsive to touch—emulating the jellyfish that inspired it.
The NUS team behind a nature-inspired electronic skin. Image courtesy of the National University of Singapore.
The collaborative project has yielded promising results after a year of experimentation.
Self-healing technologies aren’t new. NUS assistant professor Benjamin Tee, a key research contributor, helped developed the first self-healing skins back in 2012. What’s driven this new demand? Companies hope to boost underwater touchscreen functionality. Soft robotic applications also stand to benefit since they emulate human tissues.
Eight years of scientific research has centered on correcting the shortcomings of previous designs. Older skins lacked transparency and efficiency when wet.
Jellyfish: the Inspiration for the Skin
With the weaknesses of previous skins at the top of their minds, Tee’s team sought a breakthrough by thinking outside the box. Professor Tee shared their mindset:
“With this idea in mind, we began to look at jellyfishes—they are transparent and able to sense the wet environment. So, we wondered how we could make an artificial material that could mimic the water-resistant nature of jellyfishes and yet also be touch-sensitive.”
The material is inspired by jellyfish. Screenshot used courtesy of NUS News
The skin is essentially a gel, created by combining fluorocarbon polymers with fluorine-rich ionic liquid. These liquids are comprised of salt or salt-like ions. We also call these fluids “electrolyte solutions.”
This flexible membrane is printed into electronic circuits, where its conductive benefits can be realized. Because they’re self-healing, these skins have long-term longevity. The team claims this will mitigate electronic waste accumulation—especially as the technology gains traction on a wider scale.
Researchers say the "e-skin" is electrically conductive. Screenshot used courtesy of NUS News
Manufacturers can leverage 3D printing systems to make this possible. Researchers suggest that the skins will excel within low-volume applications, at least in the short term.
How Does the Skin Work?
The unique interaction between ionic fluid and the polymer base promotes self-healing via reversible di-pole reactions. This attraction between molecules stimulates the repair process.
Furthermore, past electronic skins did not react well to changing conditions. Transitioning from wet to dry environments caused those membranes to lose their structure. These new skins maintain their integrity and functionality in both instances. Professor Tee notes that neither salty, acidic, nor alkaline environments negatively impact performance, making them suitable for both marine and land applications.
The skin can stretch up to twenty times its length. Screenshot used courtesy of NUS News
Users can alter the skin’s electrical properties through touch, pressure, and strain. We commonly subject our touchscreen devices to these types of forces. The stretchiness of the skin also affects conductivity—which, according to the abstract of the Nature publication of this study, “can be tuned to as high as 10-3 S cm-1.” Researchers found they could apply strains of up to 2,000% while preserving functionality.
Soft robotics and electronics can interpret these changes, thus converting them into electrical signals. Those drive interactions while allowing sensor integration. Transparency also facilitates better environmental sensing.
Looking to the Future
Soft robotics and compatible applications are continually evolving, as does the way we interact with technology. The team at NSU recognizes that their skin can complement these future innovations. Human-machine communication seems to be a central goal.
Tee says current developments are honing in on optoelectronics. These incorporate light and other forms of radiation. We may also see fully-transparent circuit boards arise thanks to this new material. As time passes, Tee and other researchers will explore other novel avenues.
Have you dealt with touch-screen technology in the past? What were some constraints you faced? How did you overcome them? Share your experiences in the comments below.