High‐Conductivity Stoichiometric Titanium Nitride for Bioelectronics

Abstract

Bioelectronic devices such as neural stimulation and recording devices require stable low‐impedance electrode interfaces. Various forms of nitridated titanium are used in biointerface applications due to robustness and biological inertness. In this work, stoichiometric TiN thin films are fabricated using a dual Kaufman ion‐beam source setup, without the necessity of substrate heating. These layers are remarkable compared to established forms of TiN due to high degree of crystallinity and excellent electrical conductivity. How this fabrication method can be extended to produce structured AlN, to yield robust AlN/TiN bilayer micropyramids, is described. These electrodes compare favorably to commercial TiN microelectrodes in the performance metrics important for bioelectronics interfaces: higher conductivity (by an order of magnitude), lower electrochemical impedance, and higher capacitive charge injection with lower faradaicity. These results demonstrate that the Kaufman ion‐beam sputtering method can produce competitive nitride ceramics for bioelectronics applications at low deposition temperatures.

Coupling of photovoltaics with neurostimulation electrodes—optical to electrolytic transduction

“…Before deposition of the electrode material, the substrates were O 2 plasma activated. W was deposited by magnetron sputtering (100 nm, Bestec GmbH), Pt and TiN by ion beam sputtering (100 nm with 5 nm Ti sticking layer, Bestec GmbH) [55], IrO x and PtO x by reactive magnetron sputtering (240 nm, [56]). The sacrificial parylene-C was carefully peeled off under DI.…”

State‐of‐the‐Art Electronic Materials for Thin Films in Bioelectronics

“…Reproduced according to the terms of the CC BY license. [ 71 ] Copyright 2023, the authors, published by Wiley VCH.…”

“…A combination of AlN with Parylene‐C are a promising encapsulation for long‐term measurement of MEAs. [ 71 ] AlN remains underexplored in the field of bioelectronics.…”

“…Partial oxidation of the TiN surface clearly increases the capacitance by a factor of nearly 4×. Reproduced according to the terms of the CC BY license [71]. Copyright 2023, the authors, published by Wiley VCH.…”

Highly Efficient Red, Green, and Blue Inverted Top‐Emitting Organic Light‐Emitting Diodes with Microstructured TiN Substrate

“…TiN is a commonly used industrial electrode that is compatible with silicon substrates. [20][21][22] It has high melting point, high hardness, and good conductivity. [23,24] However, its light reflection performance is poor, and the OLED fabricated using TiN has low brightness and low efficiency.…”