title: Soft Anisotropic Conductors as Electric Vias for Ga-Based Liquid Metal Circuits.
abstract: We introduce a method for sealing liquid metal (LM) circuits with soft anisotropic conductors that prevent leaking, while simultaneously allowing for electrical contact with skin and surface mounted electronics. These films are composed of polydimethylsiloxane (PDMS) embedded with vertically aligned columns of ferromagnetic Ag-Ni microparticles. The microparticles are magnetically aligned and support electrical conductivity only through the thickness (z-axis) of the elastomer film. Measurements on 10-40% (by wt) composites show moderate volumetric resistivity (as low as ρ = 0.03 Ω/m) through the thickness and no conductivity between adjacent traces. Functionality is demonstrated with several illustrative applications related to tactile sensing and electronics hardware integration.
authors.affiliation: Soft Machines Lab, Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213 United States.
authors.forename: Tong
authors.initials: T
authors.lastname: Lu
authors.affiliation: Soft Machines Lab, Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213 United States.
authors.forename: James
authors.initials: J
authors.lastname: Wissman
authors.affiliation: Soft Machines Lab, Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213 United States.
authors.lastname: Ruthika
authors.affiliation: Soft Machines Lab, Department of Mechanical Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213 United States.
authors.forename: Carmel
authors.initials: C
authors.lastname: Majidi
mesh_terms: D016880:Anisotropy; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D025802:Electric Capacitance; D004553:Electric Conductivity; D005708:Gallium / Q000737:chemistry*; D006801:Humans; D008280:Magnetics; D009038:Motion; D012867:Skin; D013314:Stress, Mechanical; D013718:Tensile Strength; D014110:Touch; D014953:Wrist / Q000502:physiology
chemical_list: D004129:Dimethylpolysiloxanes; D005708:Gallium
keywords: anisotropic conductivity; conductive elastomers; eutectic gallium−indium; liquid metal; stretchable electronics