Surface electromyography (EMG) is used as a medical diagnostic and to control prosthetic limbs. Electrode arrays that provide large‐area, high density recordings have the potential to yield significant improvements in both fronts, but the need remains largely unfulfilled. Here, digital fabrication techniques are used to make scalable electrode arrays that capture EMG signals with mm spatial resolution. Using electrodes made of poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) composites with the biocompatible ionic liquid (IL) cholinium lactate, the arrays enable high quality spatiotemporal recordings from the forearm of volunteers. These recordings allow to identify the motions of the index, little, and middle fingers, and to directly visualize the propagation of polarization/depolarization waves in the underlying muscles. This work paves the way for scalable fabrication of cutaneous electrophysiology arrays for personalized medicine and highly articulate prostheses.

This article presents PEDOT:PSS/cholinium IL composites to design safe bioelectrodes for long-term cutaneous recording. The PEDOT:PSS/IL composites presented improved electronic and ionic conductivities, as well as injectable properties.

Deep Eutectic Solvents (DES) are a new class of ionic conductive compounds attracting significant attention as greener alternatives to costly ionic liquids. Herein, we developed novel mixed ionic-electronic conducting materials...

Addressing the mechanical mismatch between biological tissue and traditional electronic materials remains a major challenge in bioelectronics. While rigidity of such materials limits biocompatibility, supramolecular polymer networks can harmoniously interface with biological tissues as they are soft, wet, and stretchable. Here, an electrically conductive supramolecular polymer network that simultaneously exhibits both electronic and ionic conductivity while maintaining tissue‐mimetic mechanical properties, providing an ideal electronic interface with the human body, is introduced. Rational design of an ultrahigh affinity host–guest ternary complex led to binding affinities (>1013 M‐2) of over an order of magnitude greater than previous reports. Embedding these complexes as dynamic cross‐links, coupled with in situ synthesis of a conducting polymer, resulted in electrically conductive supramolecular polymer networks with tissue‐mimetic Young's moduli (<5 kPa), high stretchability (>500%), rapid self‐recovery and high water content (>84%). Achieving such properties enabled fabrication of intrinsically‐stretchable stand‐alone bioelectrodes, capable of accurately monitoring electromyography signals, free from any rigid materials.

Electrocardiography imaging (ECGi) is a non‐invasive inverse reconstruction procedure which employs body surface potential maps (BSPM) obtained from surface electrode array measurements to improve the spatial resolution and interpretability of conventional electrocardiography (ECG) for the diagnosis of cardiac dysfunction. ECGi currently lacks precision, which has prevented its adoption in clinical setups. The introduction of high‐density electrode arrays could increase ECGi reconstruction accuracy but is not attempted before due to manufacturing and processing limitations. Advances in multiple fields have now enabled the implementation of such arrays which poses questions on optimal array design parameters for ECGi. In this work, a novel conducting polymer electrode manufacturing process on flexible substrates is proposed to achieve high‐density, mm‐sized, conformable, long‐term, and easily attachable electrode arrays for BSPM with parameters optimally selected for ECGi applications. Temporal, spectral, and correlation analysis are performed on a prototype array demonstrating the validity of the chosen parameters and the feasibility of high‐density BSPM, paving the way for ECGi devices fit for clinical application.