Corrosion-Resistant Functional Diamond Coatings for Reliable Interfacing of Liquid Metals with Solid Metals

Abstract

Gallium-based liquid metals (GLMs) exist as atypical liquid-phase metals at and near room temperature while being electrically and thermally conductive, enabling copious applications in soft electronics and thermal management systems. Yet, solid metals are affected by interfacing with GLMs, resulting in liquid metal embrittlement and device failure. To avert this issue, mechanically durable and electrically tunable diffusion barriers for long-term reliable liquid metal−solid metal interfacing based on the deposition of various diamond coatings are designed and synthesized, as they feature high chemical inertness and extraordinary mechanical resistance. The diamond coatings show superlyophobicity (GLM contact angle ≥ 155°) and are nonstick toward GLMs, thereby achieving high mobility of GLM droplets (sliding angle 8−12°). The excellent barrier and anti-adhesion performance of the diamond coatings are proven in long-term experiments (3 weeks) of coated titanium alloy (Ti) samples in contact with GLMs. The electrical performance of the conductive diamond coating deposited on Ti is reliable and stable over a period of 50 h. As proof-of-concept applications a switch and a thermal management device based on liquid metals are demonstrated, signifying that coating diamond films on metals is a potent means to achieve stable integration of solid metals with GLMs.

Hierarchical Micro/Nanostructured Diamond Gradient Surface for Controlled Water Transport and Fog Collection

“…The water harvesting rate of the gradient film is higher than most of the fog‐collection systems. [ 16,18,35,38,55,56 ] Notably, the samples were 30° tilted with less effect by gravity. The collection efficiency can be even higher with 90° tilted samples, which was the situation in other fog‐collection systems.…”

“…Inorganic nanoparticles, [ 22,23 ] graphene, [ 24 ] carbon nanotube, [ 25,26 ] and diamond coatings [ 27 ] were introduced into this research field to address these issues. Diamond is a promising candidate as it offers plenty of outstanding properties, such as high thermal conductivity, [ 28–31 ] excellent wear resistance, [ 8,32 ] chemical inertness, [ 33,34 ] corrosion resistance, [ 35 ] quantum photonic, [ 36 ] and good biocompatibility. [ 8,37–40 ] It is possible to tailor the microstructure of the diamond coatings.…”

Ultrathin Diamond Nanofilms—Development, Challenges, and Applications

“…[120] Concurrently, the G and D bands get more pronounced (higher sp 2 content) and other features, such as a shoulder at 1148 cm −1 and a band at 1460 cm −1 , denoting the ω 1 and ω 3 vibration modes of transpolyacetylene (t-Pa), respectively, become visible. [1,121,122] Other means for characterization are SEM and HR-TEM measurements. It should be noted that analysis of the morphology of NCD or UNCD diamond coatings is difficult with SEM due to its resolution and therefore, HR-TEM is employed.…”

“…One of the biggest and most active fields of the diamond research community is the research on the conductive diamond in areas, such as high power, high frequency and high temperature electronics, [214,215] electrochemistry and electrochemical sensors, [32,[216][217][218][219][220][221][222][223][224][225] supercapacitors, [181,223,226,227] interface material for liquid metal, [1,228] photochemistry, [229] and optically transparent electrodes (OTEs). Recent reviews on conductive diamond coatings, their synthesis, properties, and applications are available.…”

“…chemical stability, and so on. [1][2][3][4][5][6][7] The great potential of this material was already discovered early, [8,9] and gave rise to significant scientific and economic import. The demand of diamond for many of the early applications was satisfied by natural diamond and the diamond synthesized by the high pressure, high temperature (HPHT) process.…”