Integrated Microfluidic Platforms on Thin Transparent Membranes, 9a

Accelerator-based x-ray spectroscopy and aberration-corrected electron microscopy are workhorse high- resolution tools for the visualizing the structure and chemistry of materials. The incredible resolving power of these techniques has historically been utilized only to study static structures because of the ultra-high vacuum requirements of the instrumentation. However, development of battery anodes and catalytic materials requires real-time characterization of liquid and gas-phase chemical dynamics. Liquid cell experiments at x-ray sources or in electron microscopes require that samples be transparent to probe beams, leak tight, and fit in transfer arms for interfacing with the ultra-high vacuum instrument chamber. Moreover, general lack of standardized interfacing with these instruments poses considerable barriers to entry for researchers seeking access to these valuable techniques because of the high capital and labor costs associated with fabricating custom sample holders for each experiment. The central objective is development of chips with electron and x-ray-transparent membrane windows, integrated electrodes, and microfluidic channels with standardized interfacing to compatible sample holders. By relegating any experimental complexity to a consumable and customizable chip, researchers will only need to procure inexpensive chips to perform their experiments, rather than both chips and custom sample holders. In the phase I program, we will design and fabricate a proof-of-concept chip with membranes, microfluidics, and electrodes. The performance of these chips in realistic environments will be evaluated. In particular, we will evaluate membrane strength and high-pressure operation. Fabrication steps including membrane growth, wafer etching, and wafer bonding will each be rigorously tested to ensure reliable operation of these chips. At the end of the Phase I, we will utilize a prototype chip to perform a realistic experiment at a beamline x-ray source. Technology advances in electron and x-ray science have helped lower the capital costs associated with these historically challenging and complex experimental techniques. As these techniques become more widely adopted, there will be a growing need to supply researchers with consumable supplies that facilitate in-situ studies of materials in environmental scenarios. The technology developed within this program will accelerate the feedback loop between capital cost reductions and widespread adoption of these tools and techniques.