High-Fidelity Electrophysiological Signal Recording from the Gastrointestinal Tract Using Soft Nanomembrane-Based Electrode Arrays

Recording electrophysiological signals from the gastrointestinal (GI) tract is critical for advancing our understanding of GI function and disorders, as well as furthering insights into the gut-brain axis. However, obtaining high-quality signals from multichannel electrode arrays on GI surfaces is challenging due to dynamic motility and the delicate nature of the GI tract. To address this, we present a novel approach for creating soft, stretchable electronics that maintain high conductivity and strain stability, even after patterning into small features. Our method involves stacking multiple layers of nanomembranes with uniform gold deposition on an elastomer substrate, achieving high conductivity (>20,000 S/cm), low sheet resistance (0.5 Ω), and superior stretchability (~500%), while preserving fine patterning down to 50 µm. These stacked gold nanomembranes are patterned via laser cutting and fabricated into multichannel electrode arrays. To further enhance performance, the electrodes are decorated with platinum particles to reduce impedance. The resulting soft electrode array is mounted onto the stomach and colon of anesthetized mice, successfully recording high signal-to-noise ratio local biopotentials from multiple locations. This precise mapping of GI electrical activity opens new avenues for exploring GI function and related disorders.