Zheng Shuquan, Chen Xuelian, Shen Kaixiang, Cheng Yilong, Ma Lei, Ming Xiaoqing
School of Materials Science and Engineering, Xi'an Shiyou University, Xi'an 710065, China.
Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, School of Chemistry, Xi'an Jiaotong University, Xi'an 710049, China.
ACS Appl Mater Interfaces. 2024 Jan 24;16(3):4035-4044. doi: 10.1021/acsami.3c16195. Epub 2024 Jan 10.
Flexible wearable sensors have demonstrated enormous potential in various fields such as human health monitoring, soft robotics, and motion detection. Among them, sensors based on ionogels have garnered significant attention due to their wide range of applications. However, the fabrication of ionogels with high sensitivity and stable autonomous adhesion remains a challenge, thereby limiting their potential applications. Herein, we present an advanced ionogel (PACG-MBAA) with exceptional performances based on multiple hydrogen bonds, which is fabricated through one-step radical polymerization of -acryloylglycine (ACG) in 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES) in the presence of ,'-methylenebis(acrylamide) (MBAA). Compared with the ionogel (PAA-MBAA) formed by polymerization of acrylic acid (AA) in EMIES, the resulting ionogel exhibits tunable mechanical strength (35-130 kPa) and Young's modulus comparable to human skin (60-70 kPa) owing to the multiple hydrogen bonds formation. Importantly, they demonstrate stable autonomous adhesion to various substrates and good self-healing capabilities. Furthermore, the ionogel-based sensor shows high sensitivity (with a gauge factor up to 6.16 in the tensile range of 300-700%), enabling the detection of both gross and subtle movements in daily human activities. By integration of the International Morse code, the ionogel-based sensor enables the encryption, decryption, and transmission of information, thus expanding its application prospects.
柔性可穿戴传感器在人体健康监测、软机器人技术和运动检测等各个领域都展现出了巨大潜力。其中，基于离子凝胶的传感器因其广泛的应用而备受关注。然而，制备具有高灵敏度和稳定自主粘附性的离子凝胶仍然是一项挑战，从而限制了它们的潜在应用。在此，我们通过在1-乙基-3-甲基咪唑鎓硫酸乙酯（EMIES）中，在N,N'-亚甲基双丙烯酰胺（MBAA）存在下，使丙烯酰甘氨酸（ACG）一步自由基聚合，制备了一种基于多重氢键的具有优异性能的先进离子凝胶（PACG-MBAA）。与在EMIES中通过丙烯酸（AA）聚合形成的离子凝胶（PAA-MBAA）相比，由于形成了多重氢键，所得离子凝胶表现出可调的机械强度（35-130 kPa）和与人体皮肤相当的杨氏模量（60-70 kPa）。重要的是，它们对各种基材表现出稳定的自主粘附性和良好的自愈能力。此外，基于离子凝胶的传感器显示出高灵敏度（在300-700%的拉伸范围内应变片系数高达6.16），能够检测日常人类活动中的大幅度和细微动作。通过集成国际摩尔斯电码，基于离子凝胶的传感器能够实现信息的加密、解密和传输，从而拓展了其应用前景。
