Jeong Seongmin, Oh Jinhyeok, Kim Hongchan, Bae Joonbum, Ko Seung Hwan
Applied Nano and Thermal Science Lab, Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
Bio-Robotics and Control Lab, Department of Mechanical Engineering, Ulsan National Institute of Science and Technology, 50 UNIST-gil, Ulsan 44919, Korea.
iScience. 2023 May 30;26(7):107008. doi: 10.1016/j.isci.2023.107008. eCollection 2023 Jul 21.
As the wearable heater is increasingly popular due to its versatile applications, there is a growing need to improve the tensile stability of the wearable heater. However, maintaining the stability and precise control of heating in resistive heaters for wearable electronics remains challenging due to multiaxial dynamic deformation with human motion. Here, we propose a pattern study for a circuit control system without complex structure or deep learning of the liquid metal (LM)-based wearable heater. The LM direct ink writing (DIW) method was used to fabricate the wearable heaters in various designs. Through the study about the pattern, the significance of input power per unit area for steady average temperature with tension was proven, and the directionality of the pattern was shown to be a factor that makes feedback control difficult due to the difference in resistance change according to strain direction. For this issue, a wearable heater with the same minimal resistance change regardless of the tension direction was developed using Peano curves and sinuous pattern structure. Lastly, by attaching to a human body model, the wearable heater with the circuit control system shows stable heating (52.64°C, with a standard deviation of 0.91°C) in actual motion.
随着可穿戴加热器因其广泛的应用而越来越受欢迎，提高可穿戴加热器的拉伸稳定性的需求也日益增长。然而，由于人体运动引起的多轴动态变形，保持可穿戴电子设备电阻加热器的稳定性和精确加热控制仍然具有挑战性。在此，我们提出了一种针对基于液态金属（LM）的可穿戴加热器的电路控制系统的图案研究，该系统无需复杂结构或深度学习。采用液态金属直接墨水书写（DIW）方法制备了各种设计的可穿戴加热器。通过对图案的研究，证明了单位面积输入功率对于拉伸状态下稳定平均温度的重要性，并且图案的方向性被证明是由于电阻变化根据应变方向不同而导致反馈控制困难的一个因素。针对这个问题，利用皮亚诺曲线和蜿蜒图案结构开发了一种无论拉伸方向如何电阻变化都最小的可穿戴加热器。最后，通过附着在人体模型上，带有电路控制系统的可穿戴加热器在实际运动中显示出稳定的加热效果（52.64°C，标准偏差为0.91°C）。
