Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongsangbuk-Do, 37673, Republic of Korea.
Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongsangbuk-Do, 37673, Republic of Korea.
Adv Sci (Weinh). 2022 May;9(16):e2200687. doi: 10.1002/advs.202200687. Epub 2022 Mar 25.
Although ion gels are attractive sensing materials for deformable epidermal sensors or implantable devices, their sensing performances are highly affected by environmental humidity change, so that their sensing reliability cannot be secured. This study proposes a new concept of maintaining the high-precision temperature sensing performance of highly deformable ion gel sensors. In this approach, a hydrophobic ion gel sensing layer is kept water-saturated by attaching a hydrogel layer, rather than attempting to completely block water penetration. This study performs experimental and theoretical investigation on water concentration in the ion gel, using the analysis of mass transportation at the interface of the ion gel and the hydrogel. By using the charge relaxation time of the ionic molecules, the temperature sensor is not affected by environmental humidity in the extreme range of humidity (30%-100%). This study demonstrates a highly deformable on-skin temperature sensor which shows the same performance either in water or dry state and while exercising with large strains (ε = 50%).
虽然离子凝胶作为可变形表皮传感器或植入式设备的传感材料很有吸引力，但它们的传感性能受环境湿度变化的影响很大，因此无法确保其传感可靠性。本研究提出了一种新概念，可维持高延展性离子凝胶传感器的高精度温度传感性能。在这种方法中，通过附着水凝胶层使疏水性离子凝胶传感层保持水饱和，而不是试图完全阻止水渗透。本研究通过对离子凝胶与水凝胶界面处传质的分析，对离子凝胶中的水浓度进行了实验和理论研究。通过分析离子分子的电荷弛豫时间，温度传感器在湿度极端范围（30%-100%）内不受环境湿度的影响。本研究展示了一种高度可变形的皮肤温度传感器，无论是在水中还是干燥状态下，甚至在大应变（ε=50%）下运动时，都能表现出相同的性能。
