Thermal management and control of wearable devices

Ju, Y. Sungtaek

doi:10.1016/j.isci.2022.104587

Cited by 20 publications

(7 citation statements)

References 85 publications

(101 reference statements)

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“…Copyright 2020, Wiley-VCH GmbH; (G) conceptual view of zebra-inspired radiative cooling membrane with TE generator; (H) energy flow of energy-harvesting system and photograph of n-and p-type Si NM TE generator array. Reproduced with permission [139] . Copyright 2023, American Association for the Advancement of Science.…”

Section: Thermoelectric Cooling Materials and Devicesmentioning

confidence: 99%

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Recent progress in thermal management for flexible/wearable devices

Yun¹

2023

Soft Sci

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Thermal management for wearable devices is evolving to make ubiquitous applications possible based on advanced devices featuring miniaturization, integration, and ultrathin designs. Thermal management and control integrated with wearable devices are highly desirable for various applications for human body monitoring, including external heat exposure and metabolic heat generation, in various activities. Recently, dynamic change materials have been integrated with micro/nano thermal management platforms to address the potential for active thermal management. In this article, recent advances in the architecture of effective thermal management in wearable devices are reviewed, along with the essential mechanisms for managing thermal conditions for users in external/internal thermal environments. Appropriate thermal management approaches are proposed for the design and integration of materials/structures tailored to specific targets in wearable devices. In particular, this review is devoted to materials/structures based on five thermal management strategies: conduction, radiation, evaporation/convection, heat absorption/release, and thermoelectric (TE). Finally, the challenges and prospects for practical applications of thermal management in wearable devices are discussed.

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Section: Thermoelectric Cooling Materials and Devicesmentioning

confidence: 99%

“…Han et al developed a zebra-pattern-inspired radiative cooling/heating system with a TE generator [139] . Figure 6G shows a dual-mode eco-resorbable cooler with strong solar reflection and IR emission made using poly(L-lactide-co-ε-caprolactone) (PLCL) as the white base material.…”

Section: Thermoelectric Cooling Materials and Devicesmentioning

confidence: 99%

Recent progress in thermal management for flexible/wearable devices

Yun¹

2023

Soft Sci

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“…17,39,40 Moreover, the rigidity of current regulators makes them mechanically incompatible with emerging soft platforms such as flexible energy storage systems, soft robotics, and wearable devices. [41][42][43][44] Hence, thermal regulators with mechanical softness and elasticity are urgently required.…”

Section: Introductionmentioning

confidence: 99%

“…To sum up, the intrinsic brittleness may result in structural damage and functional failure under external mechanical stress or internal thermal stress 17,39,40 . Moreover, the rigidity of current regulators makes them mechanically incompatible with emerging soft platforms such as flexible energy storage systems, soft robotics, and wearable devices 41–44 . Hence, thermal regulators with mechanical softness and elasticity are urgently required.…”

Section: Introductionmentioning

confidence: 99%

Flexible and elastic thermal regulator for multimode intelligent temperature control

Chen,

Yu,

Lai

et al. 2023

SusMat

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As nonlinear thermal devices, thermal regulators can intelligently respond to temperature and control heat flow through changes in heat transfer capacities, which allows them to reduce energy consumption without external intervention. However, current thermal regulators generally based on high‐quality crystalline‐structure transitions are intrinsically rigid, which may cause structural damage and functional failure under mechanical strain; moreover, they are difficult to integrate into emerging soft electronic platforms. In this study, we develop a flexible, elastic thermal regulator based on the reversible thermally induced deformation of a liquid crystal elastomer/liquid metal (LCE/LM) composite foam. By adjusting the crosslinking densities, the LCE foam exhibits a high actuation strain of 121% with flexibility below the nematic–isotropic phase transition temperature (TNI) and hyperelasticity above TNI. The incorporation of LM results in a high thermal resistance switching ratio of 3.8 over a wide working temperature window of 60°C with good cycling stability. This feature originates from the synergistic effect of fragmentation and recombination of the internal LM network and lengthening and shortening of the bond line thickness. Furthermore, we fabricate a “grid window” utilizing photic‐thermal integrated thermal control, achieving a superior heat supply of 13.7°C at a light intensity of 180 mW/cm2 and a thermal protection of 43.4°C at 1200 mW/cm2. The proposed method meets the mechanical softness requirements of thermal regulator materials with multimode intelligent temperature control.

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“…[16][17][18][19] As it is a solid-state device with no moving parts, no maintenance requirements, no noise production, and is easily integrated with other electronic components, [20][21][22][23][24][25] it has become a popular choice for thermal management in daily life and industry. [26][27][28][29][30][31][32][33] Xu et al [34] developed a flexible TE cooler with a four-layered structure of "Ag 2 Se/poly (3,4-ethylenedioxythiophene) polystyrene sulfonate" for human skin thermal management. Whether the wearer stands still or swings the arm, the skin covered by the cooler can be maintained at a comfortable temperature of 32 ± 0.5°C.…”

mentioning

confidence: 99%

Multifactor roadmap for designing low‐power‐consumed micro thermoelectric thermostats in a closed‐loop integrated 5G optical module

Yang,

Xing,

Wang

et al. 2024

Interdisciplinary Materials

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As the core components of fifth‐generation (5G) communication technology, optical modules should be consistently miniaturized in size while improving their level of integration. This inevitably leads to a dramatic spike in power consumption and a consequent increase in heat flow density when operating in a confined space. To ensure a successful start‐up and operation of 5G optical modules, active cooling and precise temperature control via the Peltier effect in confined space is essential yet challenging. In this work, p‐type Bi0.5Sb1.5Te3 and n‐type Bi2Te2.7Se0.3 bulk thermoelectric (TE) materials are used, and a micro thermoelectric thermostat (micro‐TET) (device size, 2 × 9.3 × 1.1 mm3; leg size, 0.4 × 0.4 × 0.5 mm3; number of legs, 44) is successfully integrated into a 5G optical module with Quad Small Form Pluggable 28 interface. As a result, the internal temperature of this kind of optical module is always maintained at 45.7°C and the optical power is up to 7.4 dBm. Furthermore, a multifactor design roadmap is created based on a 3D numerical model using the ANSYS finite element method, taking into account the number of legs (N), leg width (W), leg length (L), filling atmosphere, electric contact resistance (Rec), thermal contact resistance (Rtc), ambient temperature (Ta), and the heat generated by the laser source (QL). It facilitates the integrated fabrication of micro‐TET, and shows the way to enhance packaging and performance under different operating conditions. According to the roadmap, the micro‐TET (2 × 9.3 × 1 mm3, W = 0.3 mm, L = 0.4 mm, N = 68 legs) is fabricated and consumes only 0.89 W in cooling mode (QL = 0.7 W, Ta = 80°C) and 0.36 W in heating mode (Ta = 0°C) to maintain the laser temperature of 50°C. This research will hopefully be applied to other microprocessors for precise temperature control and integrated manufacturing.

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Thermal management and control of wearable devices

Cited by 20 publications

References 85 publications

Recent progress in thermal management for flexible/wearable devices

Recent progress in thermal management for flexible/wearable devices

Flexible and elastic thermal regulator for multimode intelligent temperature control

Multifactor roadmap for designing low‐power‐consumed micro thermoelectric thermostats in a closed‐loop integrated 5G optical module

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