Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
Nat Commun. 2021 Nov 19;12(1):6755. doi: 10.1038/s41467-021-27066-1.
Magnetoelastic effect characterizes the change of materials' magnetic properties under mechanical deformation, which is conventionally observed in some rigid metals or metal alloys. Here we show magnetoelastic effect can also exist in 1D soft fibers with stronger magnetomechanical coupling than that in traditional rigid counterparts. This effect is explained by a wavy chain model based on the magnetic dipole-dipole interaction and demagnetizing factor. To facilitate practical applications, we further invented a textile magnetoelastic generator (MEG), weaving the 1D soft fibers with conductive yarns to couple the observed magnetoelastic effect with magnetic induction, which paves a new way for biomechanical-to-electrical energy conversion with short-circuit current density of 0.63 mA cm, internal impedance of 180 Ω, and intrinsic waterproofness. Textile MEG was demonstrated to convert the arterial pulse into electrical signals with a low detection limit of 0.05 kPa, even with heavy perspiration or in underwater situations without encapsulations.
磁弹效应是指材料在机械变形下磁性能的变化，这种现象通常在一些刚性金属或金属合金中观察到。在这里，我们展示了磁弹效应也可以存在于具有比传统刚性对应物更强的磁机械耦合的一维软纤维中。这种效应可以通过基于磁偶极子相互作用和退磁因子的波浪链模型来解释。为了便于实际应用，我们进一步发明了一种纺织磁弹发电机（MEG），将一维软纤维与导电纱线编织在一起，将观察到的磁弹效应与磁感应耦合在一起，这为生物力学-电能转换开辟了一条新路，其短路电流密度为 0.63 mA/cm，内阻为 180 Ω，具有内在的防水性。纺织 MEG 被证明可以将动脉脉冲转换为电信号，其检测下限低至 0.05 kPa，即使在大量出汗或在水下环境中没有封装的情况下也能实现。
