Capacitively coupled arrays of multiplexed flexible silicon transistors for long-term cardiac electrophysiology

Abstract

Advanced capabilities in electrical recording are essential for the treatment of heart-rhythm diseases. The most advanced technologies use flexible integrated electronics; however, the penetration of biological fluids into the underlying electronics and any ensuing electrochemical reactions pose significant safety risks. Here, we show that an ultrathin, leakage-free, biocompatible dielectric layer can completely seal an underlying layer of flexible electronics while allowing for electrophysiological measurements through capacitive coupling between tissue and the electronics, and thus without the need for direct metal contact. The resulting current-leakage levels and operational lifetimes are, respectively, four orders of magnitude smaller and between two and three orders of magnitude longer than those of any other flexible-electronics technology. Systematic electrophysiological studies with normal, paced and arrhythmic conditions in Langendorff hearts highlight the capabilities of the capacitive-coupling approach. Our technology provides a realistic pathway towards the broad applicability of biocompatible, flexible electronic implants.

Assembly and Self‐Assembly of Nanomembrane Materials—From 2D to 3D

“…(iii) Representative voltage data obtained by the sensing system. Adapted with permission . Copyright 2017, Macmillan Publishers Limited.…”

“…A typical example is presented in Figure d. The overall system consists of 396 multiplexed capacitive sensors (18 columns, 22 rows), each with dimensions of 500 × 500 µm 2 . The system distributed uniformly over a total area of 9.5 × 11.5 mm 2 was first fabricated on Si‐on‐insulator and then transferred to a flexible substrate (panel (i) of Figure d).…”

“…The system distributed uniformly over a total area of 9.5 × 11.5 mm 2 was first fabricated on Si‐on‐insulator and then transferred to a flexible substrate (panel (i) of Figure d). Cardiac mapping experiments involve recording of unipolar voltage signals from all 396 nodes on multiple ex vivo Langendorff perfused rabbit hearts . As shown in panel (ii) of Figure d, the device conformally covers the curvilinear surface of the heart.…”

“…High‐definition electrophysiology mapping from all sensors is displayed in panel (iii) of Figure d. It is worth noting that this technology platform is important not only for cardiac applications, but also for electrophysiological sensing of other organ systems, and for use as implants in live animal models, and multiple functions can also be incorporated . In addition, if biodegradable materials are used, it is possible to obtain electronic systems which can operate in a stable, high‐performance manner for a desired time and then degrade and disappear completely as in the case of transient electronics …”

Transparent, conformable, active multielectrode array using organic electrochemical transistors

“…In addition to a function of signal amplification, an active matrix design can significantly reduce the total number of wirings to access each microelectrode, realizing a scalable MEA design. Such an active matrix addresser, realized on a flexible substrate, has been well-researched for various active components, such as OFETs, silicon membrane transistors, and nanowire transistors (2,(22)(23)(24)(25)(26)(27)(28).…”