Topological Supramolecular Network Enabled High Conductivity, Stretchable Organic Bioelectronics

Intrinsically stretchable bioelectronic devices based on soft and conducting organic materials have been regarded as the ideal interface for seamless and biocompatible integration with the human body. First, compared to rigid inorganic materials, soft organic electronic materials do not suffer from the inherent trade-off between overall system stretchability and device density. Therefore, high-resolution mapping/intervention can be realized with conformal biointerfaces. Second, the high volumetric capacitance of conducting polymers (CPs) can reduce the electrode-tissue interfacial impedance, especially at physiologically relevant frequency ranges (&lt;10 kHz), which allows high recording fidelity and efficient stimulation charge injection. However, the electrical conductivities of existing stretchable CPs are too low once they are micro-fabricated into bioelectronic devices. As a result, rigid metal interconnects are still required, which greatly diminished the advantages of soft CPs.<br/><br/>We describe here a rationally designed topological supramolecular network to simultaneously enable three significant advancements in bioelectronics. These are (i) biocompatible and stretchable CPs with high conductivity, (ii) direct photo-patternability down to cellular level feature sizes, and (iii) high stretchability maintained after micro-fabrication with no crack formation under 100% strain, which are all essential for low-impedance and seamless biointegration. The unprecedented performances of the conducting polymer with 2 orders of magnitude improvement in the conductivity under strain allow us to realize previously inaccessible applications including (i) high resolution recording of muscle signals from both human palm and highly malleable and soft-bodied octopus, and (ii) localized neuromodulation through delicate brainstem for precise controls of individual muscle activities down to single nucleus level.