时间：2017年12月13日上午10:00

地点：学院会议室2331

报告人：Ali Zavabeti  先生  以第一作者的身份在《Science》与《Nature Communications》上发表了极具影响力的文章。

欢迎各位老师及研究生参加讨论。

材料科学与工程学院

2017年12月12日

 Ali Zavabeti  于澳大利亚莫纳什大学完成了工程本科（一等荣誉）学位以及硕士学位。他在毕业后作为工程师加入了ABB（澳大利亚）并获得了长达7年在电力电子工业的工作经验。他现在为澳大利亚皇家墨尔本理工大学最后一年的博士生。他的主要研究方向为液态金属的表面属性以及制造相关的微纳米器件。他作为世界的领先者开拓了利用液态金属平台大规模制造具有单原子层厚度的二维纳米材料，并以第一作者的身份在《Science》与《Nature Communications》上发表了极具影响力的文章。同时他也以合作者的身份在包括《ACS Nano》、《Nano Letters》与《Advanced Functional Materials》等国际权威杂志上发表了多篇论文。

Liquid metal enabled micro/nano systems  (液态金属微纳米系统)

演讲摘要：

Room temperature liquid metal alloys can be utilized in many platforms and applications such as microfluidic soft actuators, makeshift mechanical components, reversible electrochemical systems, soft sensors, three dimensional printing as well as stretchable and reconfigurable electronics. Galinstan is a eutectic alloy of 68.5% gallium, 21.5% indium and 10% tin. It features a low melting point of below 0 °C and one of the highest surface tensions among all room temperature liquids. It has low toxicity and is safe to be used in laboratories and to be incorporated into consumer products. Due to the negligible vapour pressure of Galinstan it is compatible for analysis with commercial instruments requiring to operate in vacuum. Liquid metals interact with the surroundings through their surfaces. Therefore, it is crucial to explore chemical and physical properties of the surfaces of liquid metal which determine characteristics such as wettability, electrical double layer formation, droplet actuation mechanisms, deformability and surface corrosion behaviour.

In this talk, we discuss how to utilize surface properties of gallium liquid metal alloys in interface with both aqueous electrolytes and air. Former, we studied deformation and motion by breaking symmetry between two sides of a droplet with only changing the chemical composition of its surroundings (A Zavabeti et al., Nature communications, 2016). Latter, we developed facile method that provides access to ultrathin 2D oxide structures which was inaccessible before. The liquid metal is used as a reaction solvent to dissolve other, more reactive elements. Similar to most other metals, liquid metals feature an ultrathin passivating surface oxide which constitutes a naturally occurring 2D material. The research team successfully produced micrometre lateral size sheets of aluminium, hafnium and gadolinium oxide with layer thicknesses ranging between 0.5 and 1 nanometre. The methods are predicted to be suitable for producing oxide sheets of roughly one third of the elements in the periodic table. (A Zavabeti et al., Science, 2017).