Khan Mohammad R, Trlica Chris, So Ju-Hee, Valeri Michael, Dickey Michael D
Department of Chemical and Biomolecular Engineering, NC State University , Raleigh, North Carolina 27695, United States.
ACS Appl Mater Interfaces. 2014 Dec 24;6(24):22467-73. doi: 10.1021/am506496u. Epub 2014 Dec 3.
Eutectic gallium indium (EGaIn) is a promising liquid metal for a variety of electrical and optical applications that take advantage of its soft and fluid properties. The presence of a rapidly forming oxide skin on the surface of the metal causes it to stick to many surfaces, which limits the ability to easily reconfigure its shape on demand. This paper shows that water can provide an interfacial slip layer between EGaIn and other surfaces, which allows the metal to flow smoothly through capillaries and across surfaces without sticking. Rheological and surface characterization shows that the presence of water also changes the chemical composition of the oxide skin and weakens its mechanical strength, although not enough to allow the metal to flow freely in microchannels without the slip layer. The slip layer provides new opportunities to control and actuate liquid metal plugs in microchannels-including the use of continuous electrowetting-enabling new possibilities for shape reconfigurable electronics, sensors, actuators, and antennas.
共晶镓铟（EGaIn）是一种很有前景的液态金属，适用于各种利用其柔软和流体特性的电气和光学应用。金属表面迅速形成的氧化层导致它会粘附在许多表面上，这限制了根据需要轻松重新配置其形状的能力。本文表明，水可以在EGaIn与其他表面之间提供一个界面滑移层，使金属能够顺利地通过毛细管并在表面流动而不发生粘附。流变学和表面表征表明，水的存在也会改变氧化层的化学成分并削弱其机械强度，尽管还不足以使金属在没有滑移层的微通道中自由流动。该滑移层为控制和驱动微通道中的液态金属塞提供了新机会，包括使用连续电润湿，为形状可重构电子器件、传感器、致动器和天线带来了新的可能性。
