Robotic Pendant Drop: Containerless Liquid for μs-resolved, AI-executable XPCS

Abstract

X-ray Photon Correlation Spectroscopy (XPCS) probes the spontaneous fluctuation in spatial configurations of mixed phases, which can significantly impact the material properties of complex fluid. Tailored material design, however, requires navigation through massive multi-dimensional parameter space which is beyond the bandwidth of current XPCS beamline infrastructure. Using 3.7 μs-resolved XPCS, we demonstrate that Brownian dynamics of silica colloidal nanoparticles in a shielded pendant drop suspended from an electronic pipette is consistent with a sealed capillary, validating the use of pendant drop for automated XPCS measurement. Furthermore, the electronic pipette can be mounted on a robotic arm to access different stock solutions and create samples with highly-repeatable and precisely-controlled composition profiles (Video S2). This closed-loop, AI-executable experimental protocol is the first step towards autonomous material discovery and is applicable for not only XPCS, but also other high-throughput light and x-ray scattering techniques for multimodal, collaborative material characterization.

Towards a modular architecture for science factories

“…Robotic pendant drop provides an end-to-end automated, msresolved XPCS workow for studying the dynamics and structures of complex uids. Ozgulbas et al 65 recently demonstrated that Brownian dynamics of nanoparticle colloid in a pendant drop is consistent with the reference setup such as thin-walled quartz capillaries. Furthermore, the pendant drop setup can be integrated with a robotic arm (UR3e) to fully automate sample preparation, characterization, and disposal.…”