Category: IRG 1

Wisconsin MRSEC IRG 1 developed a new generative AI model for metallic glasses, called GlassVAE. The model is based on ideas similar to ChatGPT, but adapted to describe the complex atomic structures of glasses. It is designed to recognize meaningful changes in atomic structure, rather than being affected by how atoms are positioned or labeled in traditional coordinate descriptions. Unlike many general-purpose AI models that often generate unrealistic atomic arrangements, GlassVAE includes “physics guardrails” based on structural features and energy, ensuring that the generated structures remain physically sensible.

Wisconsin MRSEC IRG 1 researchers used three experimental techniques to characterize physical aging in organic semiconductor glasses. They showed that producing the glasses by physical vapor deposition can reduce the impact of aging by at least a factor of 10. In addition, they showed that routine laboratory measurements on bulk samples can provide reliable predictions for physical aging in the very thin films used in OLED displays. These results are relevant for OLED displays as glass stability is key to maintaining high efficiency, and they advance our MRSEC IRG goal to control mobility to create glasses with desirable properties.

Wisconsin MRSEC researchers have developed a coarse-graining technique called AniSOAP (for anisotropic smooth overlap of atomic potentials) that gives the beads shapes that reflect the shape of the molecules they represent. This simple idea – carefully implemented to be mathematically rigorous and account for how molecules typically interact – can used for high-accuracy coarse grained simulations or to understand materials behavior that depends on molecular shape or orientation. AniSOAP is also particularly useful for machine learning analysis of molecular behavior using simple, physically-interpretable algorithms, producing new insight for researchers.

Wisconsin MRSEC researchers have developed a new way to see how molecules fit together with an electron microscope. They used the method to see how molecules rearrange when an organic semiconductor is heated. A modest change in temperature creates significantly improved molecular alignment. The improved alignment is reflected in both larger aligned regions and straighter lines of molecules inside each region.

Physical vapor deposition (PVD) canproduce glassthinfilmswith preferred orientation to the molecules andhigherdensitythan ordinaryliquid-quenchedglass bytakingadvantageofthefastmovementoforiented moleculesonthe glasssurface.
Research supported by Wisconsin MRSEC have found a new way to control the structure and properties of these films by growing them on soft substrates. PVD on a soft substrate can produce glass thin films that are much more dense and stable than those deposited on rigid substrates. A film deposited on a soft substrate in 2 hours is equivalent to a film deposited extremely slowly on rigid substrates over ~3000 years.

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