China Researchers have made a new hybrid conductive material which is part elastic polymer and part liquid metal. The material can bend and can be stretched at will. The circuits made using this material can take 2D shapes and are non-toxic. The research work appeared on June 14 in the new interdisciplinary journal of iScience.
“These are the first flexible electronics that are at once highly conductive and stretchable, fully biocompatible, and able to be fabricated conveniently across size scales with micro-feature precision”, says Xingyu Jiang. He is a professor at the National Center for Nanoscience and Technology and senior author of this paper. His team believes that they can have a variety of applications for wearable electronics and implantable devices as well.
Figure 1 – LED circuits interconnected by MPC can bend, twist, and stretch.
Credits: Tang et al.
The researchers fashioned a material which is called as metal-polymer conductor (MPC). It is so called because it is a combination of two components. These components are very different yet have equally desirable properties. The metals are not conductive solids, such as copper, silver, or gold, but in this case they are rather gallium and indium, which exist as thick, syrupy liquids that still allows electricity to flow. The researchers found that embedding lumps of this liquid metal mixture within a supporting network of silicone-based polymer yielded mechanically strong materials. This is done inorder to make materials with enough conductivity to support functioning circuits.
The structure of this MPC can be compared to circular liquid metal islands floating in a polymer sea, with a liquid metal mantle underneath to ensure its full conductivity. They have successfully tried out various MPC formulations in a broad range of applications, including in sensors for wearable keyboard gloves and also as electrodes for stimulating the passage of DNA through the live cells membrane.
“The applications of the metal-polymer conductor (MPC) depend on the polymers“, says Lixue Tang, the first author and a graduate student in Jiang’s research group.
They cast super-elastic polymers for constructing MPCs for stretchable circuits. They use biocompatible and biodegradable polymers when they want MPCs for implantable devices. The research group has predicted that in the future, they can even build soft robots by combining electroactive polymers.
The method of researchers for manufacturing MPCs involving screen printing and microfluidic patterning, can actually accommodate any 2-D geometry, as well as various thicknesses and electrical properties, depending on the concentrations of the liquid metal inks which is to be sprayed. This flexibility could lead directly to various biomedical applications.
The researchers wanted to develop biocompatible materials that can be used to build wearable or implantable devices for diagnosing and treating disease without compromising the quality of life, and they believe that this is the first step toward changing the way that cardiovascular diseases and other afflictions are managed.
- Bunty B. Bommera
- Dakshata U. Kamble