Recent progress in thermal management for flexible/wearable devices

Abstract

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.

Wearable Aerogels for Personal Thermal Management and Smart Devices

“…Aerogel structures can be found in textiles, films, blocks, and fabrics, and their applications include temperature monitoring, pressure sensing, piezoresistive sensing, thermoelectric devices, fire alarms, health monitoring, etc. Moreover, wearable smart devices face considerable thermal stress during operation, encompassing exposure to environmental solar−thermal radiation and metabolic heat generated by the human body, 252 which exerts a substantial influence on the lifespan and efficiency of these devices. Hence, the implementation of thermal management for wearable smart devices is highly necessary.…”

Transparent Electronics for Wearable Electronics Application

“…From the device point of view, such occurrences can cause performance degradation, including the warpage of the functional layers due to thermal deformation. More critically, there are risks of thermal burns to the biological tissue due to prolonged wearing of overheated devices . Therefore, to ensure the safe use of wearable electronics in daily life, efficient and smart thermal management is required.…”

“…First, to induce efficient conduction from the curvilinear human body, it is reasonable to design composites by incorporating thermally conductive fillers into a soft polymer matrix. Commonly used polymer matrices include PDMS, TPU, and PVA, while a prominent filler is boron nitride (BN) . Metallic fillers can also effectively dissipate heat from sources, but they can critically disturb the wireless communications of wearable electronic devices.…”

“…Commonly used polymer matrices include PDMS, TPU, and PVA, while a prominent filler is boron nitride (BN). 712 Metallic fillers can also effectively dissipate heat from sources, but they can critically disturb the wireless communications of wearable electronic devices. On the other hand, BN possesses high thermal conductivity and electrical insulation properties, making it highly suitable for use in the thermal regulation layer of wearable electronics.…”

“…More critically, there are risks of thermal burns to the biological tissue due to prolonged wearing of overheated devices. 712 Therefore, to ensure the safe use of wearable electronics in daily life, efficient and smart thermal management is required. Additionally, for the optical imperceptibility of the device system discussed in this review article, transparency should also be incorporated.…”