Nucleobase-Modified Adhesive and Conductive Hydrogel Interface for Bioelectronics

Abstract

The advancement of brain–machine interface (BMI) technology has accelerated our understanding of how the brain interacts with the body through sophisticated electrophysiological signal transduction. The development of a next-generation microelectrode for BMI calls for materials with suitable mechanical properties and conductivity for fabricating bioelectronic devices. Hydrogels, known for their exceptional biocompatibility, have found widespread applications in the biomedical field. In this context, nucleobase, a fundamental building unit of the genetic material, has been introduced into polyacrylamide–poly(3,4-ethylenedioxythiophene) (PAM–PEDOT) conductive hydrogels. This innovative approach not only enhances the adhesiveness of the hydrogel to substrates due to the presence of multiple bonds at the interface but also improves the hydrogel's conductivity, mitigating the agglomeration of PEDOT particles. Moreover, the hydrogel's modulus is comparable to that of the brain tissue, which helps to reduce inflammatory reactions caused by the implantation of foreign bodies. As a result, the hydrogel has been integrated with electrodes, serving as wearable devices, electromyography electrodes, and electrocorticography electrodes, exhibiting excellent performance. This method of integrating hydrogel into implantable electrodes has shown promising results in improving biocompatibility and conductivity and minimizing inflammatory responses. This advancement opens up possibilities for enhancing the performance and long-term stability of bioelectronic devices, enabling exciting applications in the field of BMI.