Transparent and flexible low noise graphene electrodes for simultaneous electrophysiology and neuroimaging

Abstract

Calcium imaging is a versatile experimental approach capable of resolving single neurons with single-cell spatial resolution in the brain. Electrophysiological recordings provide high temporal, but limited spatial resolution, due to the geometrical inaccessibility of the brain. An approach that integrates the advantages of both techniques could provide new insights into functions of neural circuits. Here, we report a transparent, flexible neural electrode technology based on graphene, which enables simultaneous optical imaging and electrophysiological recording. We demonstrate that hippocampal slices can be imaged through transparent graphene electrodes by both confocal and two-photon microscopy without causing any light-induced artifacts in the electrical recordings. Graphene electrodes record high frequency bursting activity and slow synaptic potentials that are hard to resolve by multi-cellular calcium imaging. This transparent electrode technology may pave the way for high spatio-temporal resolution electrooptic mapping of the dynamic neuronal activity.

Thermal Release Transfer Printing for Stretchable Conformal Bioelectronics

“…The plots in Figure 3e illustrate the impedance of each channel in array. Magnitude and phase of the impedance for each channel is at the same level with the previous reported experiment result of reported Au electrode,8 indicating the ability for multichannel electrical activity recording of the stretchable neural electrode. The impedance spectra after 10.4% applied strain and 100 cyclic stretching (10.4% applied strain) are also measured, which are shown in Figures S9 and S10 (Supporting Information).…”

“…As the core of neurophysiologic monitoring, realizing high‐quality signal collection is an important topic in the research of neural electrode arrays. Related researches have indicated that stretchable/flexible neural electrode arrays, with their excellent mechanical and electrical performance, are superior candidates for the next generation of implantable devices 3, 4, 5, 6, 7, 8, 9, 10, 11. The successful development of stretchable/flexible neural electrode arrays hinges on good conformal contact between the array and the tissue, which enables excellent mechanical and electrical properties,3 as well as low‐cost, stable, and high‐throughput manufactural techniques.…”

Graphene electrodes for adaptive liquid crystal contact lenses

“…Graphene, being only one atom thick [2], and having a number of unique electrical [3], mechanical [4] and thermal [5] properties is fully compatible with flexible, curved LC devices. Furthermore, large roll to roll production of graphene [6] makes graphene a realistic candidate to be used in mass-produced flexible optoelectronic devices [7,8], organic and solid state solar cells [9,10], supercapacitors [11], neural imaging and optogenetic applications [12,13]. Recent advances in fabricating simple and low-cost graphene coated nanoprobes demonstrate the extensive potential graphene exhibits to be used in various applications and progressing its move from lab to market [14].…”

CMOS technology: a critical enabler for free-form electronics-based killer applications

“…They maintain signal quality over extended periods of time with minimized irritation and injury to brain tissues [24][25][26][27][28][29][30][31][32][33][34] . Furthermore, the gathered information from the recorded signal are comparable to that of the penetrating microelectrodes [35][36][37] .…”