Elevating Platinum to Volumetric Capacitance: High Surface Area Electrodes through Reactive Pt Sputtering.

Area of Science:

• Materials Science
• Electrochemistry
• Biomedical Engineering

Background:

• Platinum (Pt) is a primary electrode material for implantable biomedical and neuroelectronic devices.
• Improving Pt electrode performance and understanding its properties are crucial for device advancement.

Purpose of the Study:

• To explore methods for enhancing platinum electrode performance.
• To investigate the fundamental properties of a novel porous platinum oxide (PtO_x) thin film.

Main Methods:

• Preparation of PtO_x thin films using reactive magnetron sputtering.
• Partial reduction of PtO_x to create a porous platinum structure.
• Electrochemical characterization to determine impedance and capacitance.

Main Results:

• The porous PtO_x thin film demonstrated record-low impedance values, surpassing other platinum-based electrodes.
• High electrochemical capacitance was observed, scaling with film thickness, similar to volumetric capacitor materials.
• Capacitance was attributed to high surface area, not reversible pseudofaradaic reactions, distinguishing it from IrO_x and PEDOT.

Conclusions:

• The oxygen-containing porous platinum (PtO_x) offers performance competitive with iridium oxide (IrO_x) and poly(3,4-ethylenedioxythiophene) (PEDOT).
• PtO_x's high surface area contributes to its superior electrochemical properties.
• Its low cost and ease of preparation make PtO_x a promising material for microfabricated bioelectronic devices.