March 2019
Vol 5, Issue 3

About The Cover

Cover image expansion

ONLINE COVER Real-time processing and manipulation of biological signals requires bioelectronic devices with integrated components capable of signal amplification, processing, and stimulation; Transistors form the backbone of such circuits. As represented on the March cover, Spyropoulos et al. have introduced an internal-ion gated organic electrochemical transistor (IGT) that uses contained mobile ions within the conducting polymer channel to permit both volumetric capacitance and shortened ionic transit time. The IGT has high transconductance, high speed, and can be independently gated to create scalable conformable integrated circuits. The authors demonstrate the ability of the IGT to provide a miniaturized, comfortable interface with human skin, using local amplification to record high quality brain neurophysiological activity. The IGT is an effective transistor architecture for enabling integrated, real-time sensing and stimulation of signals from living organisms. The cover image highlights the conformability and biocompatibility of this transistor architecture and materials by demonstrating IGT-based digital logic gates conforming to the surface of orchid petals. Scale bar, 10 mm. [CREDIT: GEORGE SPYROPOULOS, PHD/COLUMBIA UNIVERSITY]