Polymer semiconductors, materials that have been made soft and supple but still capable of conducting electricity, hold promise for future electronics that can be integrated within the body, including disease detectors and health monitors.
Yet, until now, scientists and engineers have not been able to provide these polymers with some advanced features, such as the ability to detect biochemicals, without completely disrupting their functionality.
Researchers from the Pritzker School of Molecular Engineering (PME) have developed a new strategy to overcome this limitation. Called “click-to-polymer” or CLIP, this approach uses a chemical reaction to link new functional units to polymer semiconductors.
Using the new technique, the researchers developed a polymeric glucose monitoring device, demonstrating possible applications of CLIP in integrated electronics in humans. The findings were published August 4 in the journal Question.
“Semiconductor polymers are one of the most promising material systems for wearable and implantable electronics,” Asst said. Prof. Sihong Wang, who led the research. “But we still need to add more functionality to be able to collect signals and deliver therapies. Our method can work extensively to incorporate different types of functional groups, which we hope will lead to leaps and bounds in the field. “
Functionalizing polymers without decreasing their effectiveness
To achieve new capabilities of these semiconductor polymers, also called conjugated polymers, many researchers have previously tried to build them from scratch by directly incorporating advanced features into molecular designs. But the conventional procedures for doing this have failed, both because the molecules were unable to withstand the conditions necessary to attach them to the polymer chains, and because the synthesis process reduced their effectiveness.
To remedy this, Wang, with graduate student Nan Li, developed the CLIP method, which uses a copper-catalyzed azide-alkyne cycloaddition to add functional units to a polymer. Since this “click reaction” occurs after the polymer is created, it does not affect its initial properties much.
Not only that, the reaction could be used in polymer mass functionalization and surface functionalization, both of which are essential for creating functional electronics.
A potentially revolutionary system
To demonstrate CLIP’s effectiveness, the researchers linked units that could create a photomodel of the polymer, which is important for designing circuits within the material. They also added functionality to directly detect biomolecules. Their biomolecular sensor used a glucose oxidase enzyme to detect glucose, which then causes changes to the electrical conductance of the polymer and amplifies the signal.
Now the group is building its success by adding other bioactive and biocompatible capabilities to these polymers, which according to Li “have the potential to become a breakthrough technology.”
“We hope that researchers across the field will use our method to equip even more functionality of this material system and use them to develop the next generation of integrated human electronics as a key tool in healthcare,” said Wang.
Other authors on the paper include Yahao Dai, Yang Li, Shilei Dai, Joseph Strzalka, Qi Su, Nickolas De Oliveira, Qingteng Zhang, P. Blake J. St. Onge, Simon Rondeau-Gagné, Yunfei Wang, Xiaodan Gu, and Jie Xu.
Quote: “A universal and easy approach to the construction of multifunctional conjugated polymers for integrated electronics in humans”, Li et. to the, QUESTIONAugust 4, 2021, DOI: https://doi.org/10.1016/j.matt.2021.07.013
Funding: University of Chicago, Office of Naval Research, Department of Energy
—This story was first published on the Pritzker School of Molecular Engineering website