Researchers in the US investigate a malleable electronic skin, known as e-skin, which can turn skin into a smart interface.
The skin is one of the main organs of the human body. It is capable of sensing pressure, temperature, and many other complex environmental stimuli. Electronic skin, or e-skin, is a thin and flexible wearable device that can mimic the functional and comprehensive properties of human skin. Electronic skin may have various applications in prosthetics, biomedical devices, robotics, and human-computer interfaces. Realizing a multifunctional electronic skin that can satisfy the requirements of transparency, flexibility, and longevity, however, is still facing many challenges.
New Type of Electronic Skin
Scientists from the University of Colorado Boulder in the USA have developed a new type of self-healable and malleable electronic skin. This electronic skin has sensors tightly embedded to detect changes in pressure, flow, temperature, and humidity. What makes it special is that the electronic skin is totally recyclable, by simply soaking the device into an alcohol-based recycling solution.
In the study published recently in the journal Science Advances, Dr. J.L. Xiao and his colleagues were able to introduce a novel type of dynamic covalent bonds in between the polymer network and silver nanoparticles, achieving good thermal and electromechanical properties in an ambient environment. This electronic skin is soft and can conform to complex surfaces, such as human arms or robotic hands.
Most surprisingly, the broken electronic skin can be self-healed to recover its sensing capability and mechanical integrity by simply applying a drop of re-healing agent and hot press. Unlike other conventional thermosetting plastics that cannot be reheated and recycled, this novel electronic skin can completely dissolve in ethanol because of its reversible bond exchange through simultaneous bond forming and breaking reactions within the polymer network. The recycled ingredients can then be used to make a new, functional electronic skin.
Economical and Eco-friendly
Recent advancements in nanotechnology, polymer nanomaterials, and advanced processing methods have enabled dramatic improvements in the capabilities of systems that mimic the function of biological skin. This economical and eco-friendly technology could greatly reduce electronic waste and environmental impact, providing a bright future to reshape the future of robotic devices. Further research is needed to enhance the stretchability of the electronic skin.
Written by Man-tik Choy, Ph.D.
Reference: Zou, Z.N., et al. 2018. Rehealable, fully recyclable, and malleable electronic skin enabled by dynamic covalent thermoset nanocomposite. Science Advances, 4(2), eaaq0508. DOI 10.1126/sciadv.aaq0508