Institute for Superconducting and Electronic Materials (ISEM), Australian Institute for Innovative Materials (AIIM), University of Wollongong, Wollongong, NSW, 2500, Australia.
Department of Physics, and BUAA-UOW Joint Research Centre, Beihang University, Beijing, 100091, China.
Adv Mater. 2018 Aug;30(35):e1802595. doi: 10.1002/adma.201802595. Epub 2018 Jul 17.
Electrical communication between a biological system and outside equipment allows one to monitor and influence the state of the tissue and nervous networks. As the bridge, bioelectrodes should possess both electrical conductivity and adaptive mechanical properties matching the target soft biosystem, but this is still a big challenge. A family of liquid-metal-based magnetoactive slurries (LMMSs) formed by dispersing magnetic iron particles in a Ga-based liquid metal (LM) matrix is reported here. The mechanical properties, viscosity, and stiffness of such materials rapidly respond to the stimulus of an applied magnetic field. By varying the intensity of the magnetic field, regulation within a factor of 1000 of the Young's modulus from ≈kPa to ≈MPa, and the ability to reach GPa with more dense iron particles inside the LMMS are demonstrated. With the advantage of high conductivity of the LM matrix, the functions of the LMMS are not only limited to the soft implanted electrodes or penetrating electrodes in biosystems: the electrical response based on the LMMS electrodes can also be precisely tuned by simply regulating the applied magnetic field.
电通信在生物系统和外部设备之间建立了联系，使人们能够监测和影响组织和神经网络的状态。作为桥梁，生物电极应该同时具有导电性和适应性的机械性能，以匹配目标软生物系统，但这仍然是一个巨大的挑战。本文报道了一种由铁磁颗粒分散在镓基液态金属（LM）基体中形成的基于液态金属的磁活性浆料（LMMS）。这种材料的机械性能、粘度和硬度会对施加磁场的刺激做出快速响应。通过改变磁场的强度，可以将杨氏模量调节到约 kPa 到约 MPa 的 1000 倍范围内，并且通过在 LMMS 中添加更多密集的铁颗粒，可以达到 GPa 的模量。由于 LM 基体具有高导电性的优势，LMMS 的功能不仅限于软植入电极或穿透电极在生物系统中使用：基于 LMMS 电极的电响应也可以通过简单地调节施加的磁场来精确地进行调整。
