We showcase the potential of symbolic regression as an analytic method for use in materials research. First, we briefly describe the current state-of-the-art method, genetic programming-based symbolic regression (GPSR), and recent advances in symbolic regression techniques. Next, we discuss industrial applications of symbolic regression and its potential applications in materials science. We then present two GPSR use-cases: formulating a transformation kinetics law and showing the learning scheme discovers the well-known Johnson-Mehl-Avrami-Kolmogorov (JMAK) form, and learning the Landau free energy functional form for the displacive tilt transition in perovskite LaNiO3. Finally, we propose that symbolic regression techniques should be considered by materials scientists as an alternative to other machine-learning-based regression models for learning from data.

By virtue of the extraordinary capability of manipulating the polarization state, amplitude and phase of electromagnetic fields, metasurfaces can be employed to display holographic or nanoprinting images with unprecedented spatial resolution. Bringing holography and nanoprinting together is an effective way toward information multiplexing. However, current approaches mostly utilize interleaving or stacking nanostructures with different functionalities to construct multiplexed metasurfaces, hence they are equivalent to a combination of several metasurfaces and the information capacity of each metasurface remains unchanged. Here, by combining intensity modulation governed by Malus's law with phase manipulation based on both geometric and propagation phases, a single‐cell‐designed metasurface for three‐channel image displays is proposed. The new design strategy can significantly improve the information capacity since the extra phase modulation originates from the orientation degeneracy and dimension variation of nanostructures rather than multilayer or interleaving design. Specifically, a three‐channel metasurface is experimentally demonstrated, which can simultaneously record a continuous grayscale nanoprinting image in the near field and project two independent holographic images in the far field. With the advantages of crosstalk‐free and ultracompactness, the proposed three‐channel metasurfaces can empower the design of multifunctional nano‐optical elements for applications in image displays, optical anticounterfeiting, optical storage and many other related fields.

Local Identifier(s): UCPMS ID: 1604555eScholarship provides open access, scholarly publishing services to the University of California and delivers a dynamic research platform to scholars worldwide. Abstract:We report a discovery that perfunctionalized icosahedral dodecaborate clusters of the type B12(OCH2Ar)12 (Ar = Ph or C6F5) can undergo photo-excitation with visible light, leading to a new class of metal-free photooxidants. Excitation in these species occurs as a result of the charge transfer between low-lying orbitals located on the benzyl substituents and an unoccupied orbital delocalized throughout the boron cluster core. Here we show how these species, photo-excited with a benchtop blue LED source, can exhibit excited-state reduction potentials as high as 3 V and can participate in electron-transfer processes with a broad range of styrene monomers, initiating their polymerization. Initiation is observed in cases of both electron-rich and electron-deficient styrene monomers at cluster loadings as low as 0.005 mol%. Furthermore, photo-excitation of B12(OCH2C6F5)12 in the presence of a less activated olefin such as isobutylene results in the production of highly branched poly(isobutylene). This work introduces a new class of air-stable, metal-free photo-redox reagents capable of mediating chemical transformations.

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