论文标题
光诱导的表面张力梯度用于液体金属颗粒的层次组件
Light Induced Surface Tension Gradients for Hierarchical Assembly of Particles from Liquid Metals
论文作者
论文摘要
对于液态金属中溶解颗粒的运动的控制对于在各种纳米制作过程中的层次粒子组件的细致实现而言至关重要。布朗力可以阻碍这种颗粒的运动，从而影响可以在组装结构中实现的完美程度。在这里，我们表明，光诱导了液体金属（即液体 - 液体）中的Marangoni流动，它是laguerre-gaussian（LG）激光作为加热源，是一种有效的方法，可以在颗粒上克服布朗力，从而导致可预测的组合，并具有高度的阶数。我们表明，通过使用非高斯LG激光器在液体上进行仔细的工程表面张力梯度，在流体中发展的Marangoni和对流流驱动了随机分散的颗粒的轨迹，以组装成100 UM宽的环形颗粒组合物。仔细控制LG激光器的参数（即激光模式，斑点大小和电场强度）可以调整液体 - 液体 - 液体的温度和流体动力学以及粒子上力平衡。反过来，这可以以高度的忠诚度调整环形粒子组件的结构。使用光来控制液体金属中颗粒的运动代表了一种可调且可快速的可重新配置方法，用于在流体中设计表面张力梯度，以使颗粒和小规模溶质组装更复杂。这项工作可以扩展到各种液体金属，这与使用磁场在铁洛群中实现的粒子组件中所实现的互补。
Achieving control over the motion of dissolved particles in liquid metals is of importance for the meticulous realization of hierarchical particle assemblies in a variety of nanofabrication processes. Brownian forces can impede the motion of such particles, impacting the degree of perfection that can be realized in assembled structures. Here we show that light induced Marangoni flow in liquid metals (i.e., liquid-gallium) with Laguerre-gaussian (LG) lasers as heating sources, is an effective approach to overcome Brownian forces on particles, giving rise to predictable assemblies with high degree of order. We show that by carefully engineering surface tension gradients in liquid-gallium using non-gaussian LG lasers, the Marangoni and convective flow that develops in the fluid drives the trajectory of randomly dispersed particles to assemble into 100 um wide ring-shaped particle assemblies. Careful control over the parameters of the LG laser (i.e., laser mode, spot size, and intensity of the electric field) can tune the temperature and fluid dynamics of the liquid-gallium as well as the balance of forces on the particle. This in turn can tune the structure of the ring-shaped particle assembly with a high degree of fidelity. The use of light to control the motion of particles in liquid metals represents a tunable and rapidly reconfigurable approach to spatially design surface tension gradients in fluids for more complex assembly of particles and small-scale solutes. This work can be extended to a variety of liquid-metals, complementary to what has been realized in particle assembly out of ferrofluids using magnetic fields.
