US researchers develop organic polymer electronics that can heal themselves

Organic polymers that conduct electricity could lead to biodegradable electronics and self-repairing systems according to researchers at the University of California Merced.

These polymers are expected to enable devices that can self-repair when cracked or broken, or allow electronics to be incorporated into textiles, clothing, or as health monitoring devices on an individual’s skin. Once these devices are finished with, they could biodegrade or be recycled as part of a zero-waste economy. It is conjugated polymers that are expected to realise these properties. Conjugated polymers are organic macromolecules that have a backbone molecular chain of alternating double and single atomic bonds. These double and single bonds result in useful optical and electronic properties.

“With synthetic polymers, we can infuse virtually any desired electrical, mechanical or optical properties because we get to create them in the lab,” said University of California Merced assistant professor Yue Wang. “They can be made stretchable, self-healing and biodegradable — properties we don’t commonly associate with electronics. They are becoming the building blocks for all kinds of innovations.”

Wang is an assistant professor of Materials Science and Engineering and chemistry and chemical biology. Her structural electronics laboratory has three main research areas, biomimetic electronic materials, additive manufacturing of functional polymers and organic structural metamaterials. The lab's staff include scientists and engineers working on polymer synthesis, mechanics, device fabrication and additive manufacturing. Additive manufacturing conducting polymers which have been designed at the molecular level are expected to make the electronics damage tolerant.

Biomimetic electronic materials are about making electronics mirror the human body's properties, such as flexibility. The biomimetic materials act as building blocks for biomedical devices that can be customised for individual patients and detect, sense, and even stimulate biomarkers. The lab is also developing organic conductors that can mimic the mechanical and physiological properties and hierarchical structures of biological systems.

The effort to create these biodegradable electronics is multidisciplinary and Wang has nine undergraduate students, six graduate students and one postdoctoral researcher. Their backgrounds include, bioengineering, chemistry, mechanical engineering and materials science. “This is very interdisciplinary work,” Wang said, “and the projects have a lot of components.”

Biodegradable electronics could be part of a zero-waste economy, where all waste s recycled. “They let us consider the whole life of a product, because when they are no longer needed, they can be recycled or re-processed and reused, or they will biodegrade without causing any harm in landfills,” Wang’s postdoctoral researcher, Robert Jordan, explained.

Wang earned a USD$25,000 award for being a finalist of the Gordon and Betty Moore Foundation’s Moore Inventor Fellowships. Wang’s fellowship proposal was bio-inspired, environmentally sustainable electronics. Organic electronics may be able to reduce the problem of toxic electronic waste as those metals will not be used or used less. The Moore fellowships aim to support inventors that may shape the next 50 years of science and technology.