{"id":3062615,"date":"2024-01-15T09:34:00","date_gmt":"2024-01-15T14:34:00","guid":{"rendered":"https:\/\/platoaistream.com\/plato-data\/revolutionary-transparent-graphene-microelectrodes-enhance-brain-imaging-and-stimulation\/"},"modified":"2024-01-15T09:34:00","modified_gmt":"2024-01-15T14:34:00","slug":"revolutionary-transparent-graphene-microelectrodes-enhance-brain-imaging-and-stimulation","status":"publish","type":"station","link":"https:\/\/platoaistream.com\/plato-data\/revolutionary-transparent-graphene-microelectrodes-enhance-brain-imaging-and-stimulation\/","title":{"rendered":"Revolutionary transparent graphene microelectrodes enhance brain imaging and stimulation"},"content":{"rendered":"
In a recent study published in Nature Nanotechnology<\/em><\/a>,<\/em> a group of researchers developed high-density, ultrasmall, transparent graphene microelectrodes for enhanced spatial resolution in brain surface electrophysiological recordings and calcium imaging, enabling the decoding of single-cell and average neural activities from surface potentials.<\/p>\n <\/span><\/span><\/a>Study: High-density transparent graphene arrays for predicting cellular calcium activity at depth from surface potential recordings<\/a>. Image Credit: Gorodenkoff\/Shutterstock.com<\/em><\/p>\n Exploring brain mechanisms across diverse spatial and temporal scales is essential for understanding neural dynamics, necessitating tools that integrate various modalities.<\/p>\n Traditional transparent microelectrode technologies, despite their advancements, are limited by size and channel density.<\/p>\n Further research is needed to enhance the integration of these technologies with living neural tissue, optimize long-term stability and biocompatibility, and expand their application to a wider range of neurological studies and therapeutic interventions.<\/p>\n The researchers developed high-density transparent graphene arrays by depositing a perylene C (PC) layer on a silicon wafer with a sacrificial layer of Polydimethylglutarimide (PMGI) SF3.<\/p>\n They then sputtered chromium and gold to form metal wires and contact pads. The first graphene layer was transferred using electrochemical delamination, and to reduce wire resistance, it was immersed in a nitric acid (HNO3) solution.<\/p>\n After cleaning, a second graphene layer was added. They used a bilayer photoresist and etched the graphene with oxygen plasma, followed by cleaning. To protect the graphene during subsequent steps, they sputtered a silicon dioxide etch-stop layer on it.<\/p>\n After depositing and patterning another PC layer as the encapsulation layer, they removed the silicon dioxide layer to access the graphene and detached the arrays from the wafer.<\/p>\n For the electrode characterization, the team conducted electrochemical deposition of platinum nanoparticles (PtNPs) and electrochemical characterizations using a Gamry 600 plus in a phosphate-buffered saline solution.<\/p>\n Measurements were made in a Faraday cage to avoid electromagnetic noise. PtNP deposition was executed in a two-electrode configuration with a current flown from the graphene electrode to the counter electrode.<\/p>\n The impedance of the electrodes was found to saturate after 150 seconds of PtNP deposition.<\/p>\n <\/p>\n The researchers modified the conventional Randles model to analyze the electrodes, capturing the quantum capacitance effect, the resistance of graphene wires, and pseudo-capacitance (Cp) of PtNP.<\/p>\n They removed the quantum capacitance component from the equivalent circuit model for the electrode\/electrolyte interface, adding Cp and charge-transfer resistance (Rct) to represent the pseudo-capacitance of PtNP. Capacitances in the circuit models were extracted by fitting electrochemical impedance spectroscopy measurement data.<\/p>\nBackground <\/h2>\n
About the study<\/h2>\n