UCLA

Understanding how to tune molecular assemblies and the properties of surfaces of different materials at the meso- and nanoscales can lead to unique and controllable interactions at interfaces for a variety of applications. I used dipolar forces to control the adsorption and alignment of liquid crystals (LCs), which are highly sensitive to surface interactions. This work utilized carboranethiol and -dithiol isomers, which possess the same geometry and lattice when self-assembled on Au{111}, but differ in the magnitude and direction of their dipole moments. Hence, self-assembled monolayers (SAMs) of carboranethiol isomers enabled us to deconvolve dipole interactions from other factors that influence LC alignment. We fabricated LC devices using carboranethiol SAMs on transparent gold surfaces, prepared by oblique evaporation, and measured the LC orientation and anchoring energy on surfaces treated with each isomer. These results suggested that the dipole moment direction strongly influences the LC alignment and anchoring energy.

In the second part of my dissertation, I used bioinspired omniphobic surface coating for rapid cell deformation devices to enable high-throughput intracellular cargo delivery. Currently, devices clog within minutes, rendering them inefficient for sustainable cell processing. We have developed a method for coating commercial poly(tetrafluoroethylene) syringe and poly(ethylene terephthalate) filters with slippery liquid-infused porous surfaces (SLIPS). We see that without this coating, essentially no cells are recovered from the device, due to clogging. However, with the SLIPS coating, we are able to recover 25-50% of cells. Additionally, we have successfully delivered a green fluorescent protein plasmid and a CD19 chimeric antigen receptors to Jurkat cells, a model T lymphocyte cell line, while maintaining high cell viability. These devices made from economical commercial materials will enable new opportunities in the development of gene and cellular therapies for a wide variety of disease treatments, which are currently limited due to toxicity, low throughput, and off-target effects.