Multi‐Electrode Printed Bioelectronic Patches for Long‐Term Electrophysiological Monitoring

Abstract

A novel architecture of materials and fabrication techniques is proposed that serves as a universal method for implementation of thin-film biostickers for high resolution electrophysiological monitoring. Unlike the existing wearable patches, the presented solution can be worn for several days, and is not affected by daily routines such as physical exercise or taking bath. A printable biphasic liquid metal silver composite is used, both as the electrical interconnects and the electrodes. This allows combining advantages of dry electrodes, i.e., printability and non-smearing behavior, with benefits of wet electrodes, i.e., high-quality signal. A human subject study showed that these biphasic printed electrodes benefit from a lower electrode-skin impedance compared to clinical grade Ag/AgCl electrodes. Digital printing enables autonomous fabrication of biostickers that are taylor-made for each user and each application. A universal miniaturized electronic system for biopotential acquisition and wireless communication is develpoed, and demonstrated multiple biopotential acquisition cases, including electrocardiography, electroencephalography, electromyography, and electrooculography.

Recyclable Thin‐Film Soft Electronics for Smart Packaging and E‐Skins

“…Moreover, the fact that these printed electrodes are dry (i.e., no wet gel or electrolyte‐rich conductive paste is interfacing them with the skin) decreases the chances of electrode cross‐talk or electrode‐skin interface degradation over time due to electrolyte drying, as previously discussed. [[ 65 ]]…”

“…The patch was connected to a miniaturized biopotential recording system previously presented [ 65 ] through a flat cable and the electrophysiological recordings were sent by the analog front end (AFE) via UDP protocol and acquired by the OpenBCI GUI (v5.0.9 for Mac) and later converted to CSV files. The full acquisition setup is shown in Figure S37 (Supporting Information).…”

Functional heterophasic liquid metals

“…The resulting composites are conductive, stretchable, and thus useful for stretchable electronics. [71][72][73] For example, the electrical limitation can be eliminated by coating highly conductive metals on the surface of LM micro or nanoparticles (GRR). [61] As shown in Figure 2a, the metallic core-shell structure is available through the galvanic replacement between alkaline KAuBr 4 and LMs with the aid of surfactants.…”

“…To realize electrically conductive LM composites, researchers have added solid metal particles (Cu, Ag, Ni, and W) into LM. The resulting composites are conductive, stretchable, and thus useful for stretchable electronics [71–73] . For example, the electrical limitation can be eliminated by coating highly conductive metals on the surface of LM micro or nanoparticles (GRR) [61] .…”

Implantable neural electrodes: from preparation optimization to application

“…1 Electrophysiological signals include electrocardiogram (ECG), electroencephalogram (EEG), electromyogram (EMG) and electrooculogram (EOG) signals. 2 The monitoring of these signals can judge the function and status of nerves, muscles and organs, which is of great significance for the prevention and treatment of diseases. 3 The electrical signal can be monitored by a neural electrode and the information can be decoded, which has important applications in frontier fields, such as brain research, bioelectronics and medicine, and artificial prostheses.…”