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Recycling of polyurethanes is largely infeasible due to the harsh reprocessing conditions and associated risks of side reactions and degradation whereas polymer networks incorporating dynamic covalent bonds represent an attractive approach to the design of recyclable materials. Here, we report findings on the dynamic nature of thiourethanes, and their application as a new class of recyclable analogs of urethane materials. A series of small molecule experiments was initially conducted to determine the equilibrium constant and exchange reaction kinetic constant for the thiol–isocyanate reaction. Furthermore, incorporating those thiourethane moieties into a cross-linked network resulted in thermoset materials that are readily depolymerized to liquid oligomers. The resultant oligomers can be re-crosslinked to thiourethanes without any loss of performance nor change in mechanical properties (peak stress of 25 MPa with max strain of 200%). Moreover, the recycled thiol oligomers from thiourethane network polymers could potentially be transformed into other materials with mechanical properties that exceed those of the initial, pristine thiourethane materials. Overall, the ease with which these polythiourethanes are polymerized, recycled and reformulated gives a new direction and hope in the design of sustainable polymers. 

Abstract Silicone‐based devices have the potential to achieve an ideal interface with nervous tissue but suffer from scalability, primarily due to the mechanical mismatch between established electronic materials and soft elastomer substrates. This study presents a novel approach using conventional electrode materials through multifunctional nanomesh to achieve reliable elastic microelectrodes directly on polydimethylsiloxane (PDMS) silicone with an unprecedented cellular resolution. This engineered nanomesh features an in‐plane nanoscale mesh pattern, physically embodied by a stack of three thin‐film materials by design, namely Parylene‐C for mechanical buffering, gold (Au) for electrical conduction, and Poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) for improved electrochemical interfacing. Nanomesh elastic neuroelectronics are validated using single‐unit recording from the small and curvilinear epidural surface of mouse dorsal root ganglia (DRG) with device self‐conformed and superior recording quality compared to plastic control devices requiring manual pressing is demonstrated. Electrode scaling studies from in vivo epidural recording further revealed the need for cellular resolution for high‐fidelity recording of single‐unit activities and compound action potentials. In addition to creating a minimally invasive device to effectively interface with DRG sensory afferents at a single‐cell resolution, this study establishes nanomeshing as a practical pathway to leverage traditional electrode materials for a new class of elastic neuroelectronics.