Shin, Gilyong Baek, Jae Yoon Kim, Ju Hyeon Lee, Ju Hwan Kim, Hyeong Jun So, Byeong Jun Choi, Yuseung Yun, Sungryul Kim, Taewoo Jeon, Jei Gyeong Kang, Tae June 2024-11-07T02:00:58Z 2024-11-07T02:00:58Z 2024-11-06 2025-03 1616-301X https://pubs.kist.re.kr/handle/201004/150997 Quasi-solid-state thermocells (QTECs) show promise as a power source for wearable devices by converting body heat into electricity. While significant progress has been made with p-type elements for QTECs, challenges remain with their n-type counterparts. Here, a high-performance n-type QTEC element is presented, using a copolymer hydrogel that outperforms conventional p-type elements. This copolymer hydrogel combines hydrophilic zwitterionic sulfobetaine methacrylate (SBMA) for ionic conduction and hydrophobic methyl methacrylate (MMA) for structural stability. By increasing the MMA content from 35 to 100 wt.%, versatile control is achieved over the hydrogel's elastic modulus (72 kPa to 127.7 MPa) and tensile strength (54 kPa to 6.7 MPa). A high mechanical toughness of 7.2 MJ m-3 is also achieved at 68 wt.% MMA. The mechanically robust and high toughness p(SBMA-MMA) hydrogel is then immersed in Fe(ClO4)2/3 solutions of different concentrations to evaluate its performance as an n-type QTEC element. The hydrogel with 0.8 M Fe(ClO4)2/3 exhibits a high ionic Seebeck coefficient of -1.7 mV K-1, a power density of 1.1 mW m-2 K-2, and an elastic modulus of 1.6 MPa, which is similar to that of human skin. Finally, the optimized n-type p(SBMA-MMA) hydrogels demonstrate the potential application for wearable devices. A high-performance n-type element for quasi-solid-state thermocells has been introduced, outperforming conventional p-type elements and showcasing the potential to harness body heat as an energy source or power embedded sensors. This advance significantly contributes to waste thermal energy harvesting and wearable technology, paving the way for self-powered wearable devices. image English John Wiley & Sons Ltd. Mechanically Adaptable High-Performance p(SBMA-MMA) Copolymer Hydrogel with Iron (II/III) Perchlorate for Wearable Thermocell Applications Article 10.1002/adfm.202412524 1 Advanced Functional Materials, v.35, no.12 Advanced Functional Materials 35 12 Y scie scopus 001336343600001 2-s2.0-85206681578 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article IONS THERMOGALVANIC CELLS TOUGH ELECTROLYTES THERMOPOWER STIFFNESS hydrogel iron (II/III) perchlorate sulfobetaine methacrylate thermocell wearables