Lightweight, Thermally Conductive Liquid Metal Elastomer Composite with Independently Controllable Thermal Conductivity and Density

Small ◽  
2021 ◽  
pp. 2104762
Author(s):  
Ethan J. Krings ◽  
Haipeng Zhang ◽  
Suchit Sarin ◽  
Jeffery E. Shield ◽  
Sangjin Ryu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Metal ◽  
Conductive Liquid ◽  
Thermally Conductive

scholarly journals Nano liquid metal for the preparation of a thermally conductive and electrically insulating material with high stability

RSC Advances ◽  
2018 ◽  
Vol 8 (29) ◽  
pp. 16232-16242 ◽  
Author(s):  
P. Fan ◽  
Z. Sun ◽  
Y. Wang ◽  
H. Chang ◽  
P. Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Metal ◽  
High Stability ◽  
Insulating Material ◽  
Conductive Materials ◽  
Thermally Conductive ◽  
Base Polymer

Compared to liquid metal (LM) microdroplets based thermally conductive materials (micro-LM-THEMs), nano LM-THEMs (nLM-THEMs) presents a more stable electric insulating property even upon stress, achieving ~50-fold thermal conductivity over base polymer.

scholarly journals High thermal conductivity in soft elastomers with elongated liquid metal inclusions

2017 ◽  
Vol 114 (9) ◽  
pp. 2143-2148 ◽  
Author(s):  
Michael D. Bartlett ◽  
Navid Kazem ◽  
Matthew J. Powell-Palm ◽  
Xiaonan Huang ◽  
Wenhuan Sun ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Liquid Metal ◽  
Heat Dissipation ◽  
Dielectric Materials ◽  
Phonon Transport ◽  
High Thermal Conductivity ◽  
Stretchable Electronics ◽  
Mechanical Stiffness ◽  
Mechanical Coupling ◽  
Thermally Conductive

Soft dielectric materials typically exhibit poor heat transfer properties due to the dynamics of phonon transport, which constrain thermal conductivity (k) to decrease monotonically with decreasing elastic modulus (E). This thermal−mechanical trade-off is limiting for wearable computing, soft robotics, and other emerging applications that require materials with both high thermal conductivity and low mechanical stiffness. Here, we overcome this constraint with an electrically insulating composite that exhibits an unprecedented combination of metal-like thermal conductivity, an elastic compliance similar to soft biological tissue (Young’s modulus < 100 kPa), and the capability to undergo extreme deformations (>600% strain). By incorporating liquid metal (LM) microdroplets into a soft elastomer, we achieve a ∼25× increase in thermal conductivity (4.7 ± 0.2 W⋅m−1⋅K−1) over the base polymer (0.20 ± 0.01 W⋅m−1·K−1) under stress-free conditions and a ∼50× increase (9.8 ± 0.8 W⋅m−1·K−1) when strained. This exceptional combination of thermal and mechanical properties is enabled by a unique thermal−mechanical coupling that exploits the deformability of the LM inclusions to create thermally conductive pathways in situ. Moreover, these materials offer possibilities for passive heat exchange in stretchable electronics and bioinspired robotics, which we demonstrate through the rapid heat dissipation of an elastomer-mounted extreme high-power LED lamp and a swimming soft robot.

Thermally Conductive and Highly Electrically Resistive Grease Through Homogeneously Dispersing Liquid Metal Droplets Inside Methyl Silicone Oil

2014 ◽  
Vol 136 (1) ◽  
Author(s):  
Shengfu Mei ◽  
Yunxia Gao ◽  
Zhongshan Deng ◽  
Jing Liu
Keyword(s):  
Liquid Metal ◽  
Electronic Packaging ◽  
Room Temperature ◽  
Silicone Oil ◽  
Thermal Interface Material ◽  
Pure Liquid ◽  
Methyl Silicone ◽  
Conductive Liquid ◽  
Thermally Conductive ◽  
Temperature Liquid

Thermal grease, as a thermal interface material (TIM), has been extensively applied in electronic packaging areas. Generally, thermal greases consist of highly thermally conductive solid fillers and matrix material that provides good surface wettability and compliance of the material during application. In this study, the room-temperature liquid metal (a gallium, indium and tin eutectic, also called Galinstan) was proposed as a new kind of liquid filler for making high performance TIMs with desired thermal and electrical behaviors. Through directly mixing and stirring in air, liquid metal micron-droplets were accidentally discovered capable to be homogeneously distributed and sealed in the matrix of methyl silicone oil. Along this way, four different volume ratios of the liquid metal poly (LMP) greases were fabricated. The thermal and electrical properties of the LMP greases were experimentally investigated, and the mechanisms were clarified by analyzing their surface morphologies. The experimental results indicate that the original highly electrically conductive liquid metal can be turned into a highly electrically resistive composite, by simply blending with methyl silicone oil. When the filler content comes up to 81.8 vol. %, the thermal conductivity, viscosity and volume resistivity read 5.27 W/(m · °C), 760 Pa · s and 1.07 × 107 Ω m, respectively. Furthermore, the LMP greases presented no obvious corrosion effect, compared with pure liquid metal. This study opens a new approach to flexibly modify the material behaviors of the room-temperature liquid metals. The resulted thermally conductive however highly electrically resistive LMP greases can be significant in a wide variety of electronic packaging applications.

Highly thermally conductive liquid metal-based composites with superior thermostability for thermal management

2021 ◽  
Author(s):  
Li-Chuan Jia ◽  
Yi-Fei Jin ◽  
Jun-Wen Ren ◽  
Li-Hua Zhao ◽  
Ding-Xiang Yan ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Thermal Management ◽  
Conductive Liquid ◽  
Thermally Conductive

Mechanically strong and thermostable composites are prepared for thermal management based on soft liquid metal and rigid aramid nanofibers.

Highly thermally conductive UHMWPE/NG composites with the segregated structure and their application for heat spreader

2020 ◽  
pp. 089270572096564
Author(s):  
Xiao Wang ◽  
Hui Lu ◽  
Jun Chen
Keyword(s):  
Thermal Conductivity ◽  
Laser Flash ◽  
Heating Process ◽  
X Ray Diffraction ◽  
Heat Spreader ◽  
Conductive Composites ◽  
Compression Direction ◽  
Thermal Analyzer ◽  
Thermally Conductive ◽  
Plane Direction

In this work, ultra-high molecular weight polyethylene (UHMWPE)/natural flake graphite (NG) polymer composites with the extraordinary high thermal conductivity were prepared by a facile mixed-heating powder method. Morphology observation and X-ray diffraction (XRD) tests revealed that the NG flakes could be more tightly coated on the surface of UHMWPE granules by mixed-heating process and align horizontally (perpendicular to the hot compression direction of composites). Laser flash thermal analyzer (LFA) demonstrated that the thermal conductivity (TC) of composites with 21.6 vol% of NG reached 19.87 W/(m·K) and 10.67 W/(m·K) in the in-plane and through-plane direction, respectively. Application experiment further demonstrated that UHMWPE/NG composites had strong capability to dissipate the heat as heat spreader. The obtained results provided a valuable basis for fabricating high thermal conductive composites which can act as advanced thermal management materials.

scholarly journals Enhancement of the Thermal Performance of the Paraffin-Based Microcapsules Intended for Textile Applications

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1120
Author(s):  
Virginija Skurkyte-Papieviene ◽  
Ausra Abraitiene ◽  
Audrone Sankauskaite ◽  
Vitalija Rubeziene ◽  
Julija Baltusnikaite-Guzaitiene
Keyword(s):  
Thermal Conductivity ◽  
Thermal Performance ◽  
Comparative Method ◽  
Multiwall Carbon Nanotubes ◽  
Acrylic Resin ◽  
Positive Influence ◽  
Outer Shell ◽  
Ir Camera ◽  
Spacer Fabric ◽  
Thermally Conductive

Phase changing materials (PCMs) microcapsules MPCM32D, consisting of a polymeric melamine-formaldehyde (MF) resin shell surrounding a paraffin core (melting point: 30–32 °C), have been modified by introducing thermally conductive additives on their outer shell surface. As additives, multiwall carbon nanotubes (MWCNTs) and poly (3,4-ethylenedioxyoxythiophene) poly (styrene sulphonate) (PEDOT: PSS) were used in different parts by weight (1 wt.%, 5 wt.%, and 10 wt.%). The main aim of this modification—to enhance the thermal performance of the microencapsulated PCMs intended for textile applications. The morphologic analysis of the newly formed coating of MWCNTs or PEDOT: PSS microcapsules shell was observed by SEM. The heat storage and release capacity were evaluated by changing microcapsules MPCM32D shell modification. In order to evaluate the influence of the modified MF outer shell on the thermal properties of paraffin PCM, a thermal conductivity coefficient (λ) of these unmodified and shell-modified microcapsules was also measured by the comparative method. Based on the identified optimal parameters of the thermal performance of the tested PCM microcapsules, a 3D warp-knitted spacer fabric from PET was treated with a composition containing 5 wt.% MWCNTs or 5 wt.% PEDOT: PSS shell-modified microcapsules MPCM32D and acrylic resin binder. To assess the dynamic thermal behaviour of the treated fabric samples, an IR heating source and IR camera were used. The fabric with 5 wt.% MWCNTs or 5 wt.% PEDOT: PSS in shell-modified paraffin microcapsules MPCM32D revealed much faster heating and significantly slower cooling compared to the fabric treated with the unmodified ones. The thermal conductivity of the investigated fabric samples with modified microcapsules MPCM32D has been improved in comparison to the fabric samples with unmodified ones. That confirms the positive influence of using thermally conductive enhancing additives for the heat transfer rate within the textile sample containing these modified paraffin PCM microcapsules.

scholarly journals Advances in Liquid Crystalline Epoxy Resins for High Thermal Conductivity

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1302
Author(s):  
Younggi Hong ◽  
Munju Goh
Keyword(s):  
Thermal Conductivity ◽  
Network Structure ◽  
Epoxy Resins ◽  
Liquid Crystalline ◽  
Random Network ◽  
Three Dimensional ◽  
Heat Insulator ◽  
Liquid Crystalline Epoxy ◽  
Thermally Conductive ◽  
Substantial Interest

Epoxy resin (EP) is one of the most famous thermoset materials. In general, because EP has a three-dimensional random network, it possesses thermal properties similar to those of a typical heat insulator. Recently, there has been substantial interest in controlling the network structure of EP to create new functionalities. Indeed, the modified EP, represented as liquid crystalline epoxy (LCE), is considered promising for producing novel functionalities, which cannot be obtained from conventional EPs, by replacing the random network structure with an oriented one. In this paper, we review the current progress in the field of LCEs and their application to highly thermally conductive composite materials.

scholarly journals Improving the Actuation Speed and Multi-Cyclic Actuation Characteristics of Silicone/Ethanol Soft Actuators

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 62 ◽  
Author(s):  
Boxi Xia ◽  
Aslan Miriyev ◽  
Cesar Trujillo ◽  
Neil Chen ◽  
Mark Cartolano ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Short Term Memory ◽  
Conductive Filler ◽  
Thermally Driven ◽  
Thermally Conductive ◽  
Ethanol Evaporation ◽  
Long Short Term Memory ◽  
Soft Actuators ◽  
Robotic Applications ◽  
Soft Composite

The actuation of silicone/ethanol soft composite material-actuators is based on the phase change of ethanol upon heating, followed by the expansion of the whole composite, exhibiting high actuation stress and strain. However, the low thermal conductivity of silicone rubber hinders uniform heating throughout the material, creating overheated damaged areas in the silicone matrix and accelerating ethanol evaporation. This limits the actuation speed and the total number of operation cycles of these thermally-driven soft actuators. In this paper, we showed that adding 8 wt.% of diamond nanoparticle-based thermally conductive filler increases the thermal conductivity (from 0.190 W/mK to 0.212 W/mK), actuation speed and amount of operation cycles of silicone/ethanol actuators, while not affecting the mechanical properties. We performed multi-cyclic actuation tests and showed that the faster and longer operation of 8 wt.% filler material-actuators allows collecting enough reliable data for computational methods to model further actuation behavior. We successfully implemented a long short-term memory (LSTM) neural network model to predict the actuation force exerted in a uniform multi-cyclic actuation experiment. This work paves the way for a broader implementation of soft thermally-driven actuators in various robotic applications.

Sign in / Sign up

Export Citation Format

Share Document