Fig. 4. Liquid metal-based conductive inks.

a The O-GaIn liquid metal (LM) features a uniform distribution of air holes and Ga_xO_y particles, schematic of the LM in situ fabrication process, and LM as electrodes on human skin. Reprinted with permission from Liu et al.¹⁴. Copyright 2019 WILEY-VCH. b Schematic of O-GaIn conformable bioelectrodes positioned on in vivo tumors while under an alternating magnetic field. Reprinted with permission from Liu et al.¹⁴. Copyright 2019 WILEY-VCH. c Schematic of the Ni-EGaIn electrodes (top) and recorded ECG signals from the Ni-EGaIn and Ag/AgCl electrodes as a comparison (bottom). Reprinted with permission from Deng et al.¹³. Copyright 2019 WILEY-VCH. d Adhesive liquid metal particle (ALMP) ink micropatterned on a human hand (top) and interaction between LM, PVA, and top layer of skin (bottom). Reprinted with permission from Jiang et al.¹⁶. Copyright 2022 WILEY-VCH. e Schematic of the direct coating process using the LMP covered with Pt-decorated carbon nanotubes ink. Reprinted with permission from Park et al.¹⁷. Copyright 2022 WILEY-VCH.