Photoacoustic characterization of an ultrasound-transparent high-density surface EMG array

We present a photoacoustic characterization of a high-density, ultrasound-transparent surface EMG electrode array designed for multimodal biomedical imaging. While such electrodes have been shown to preserve ultrasound image quality, their interaction with photoacoustic signals has remained unexplored. Using a tissue-mimicking phantom with embedded absorbers, we evaluated signal transmission through the electrode array across wavelengths from 690 to 950 nm. Signal-to-noise ratio analysis revealed minimal attenuation, particularly between 750 and 850 nm. These findings support the feasibility of integrating such arrays into hybrid photoacoustic and electrophysiological systems for co-registered electrophysiological and photoacoustic monitoring in biomedical applications.