Boechler Research Group

Dynamics of self-assembled nanomaterials

While there is significant functionality potential for nanomaterials, there is a problem for manufacturing them at scale using conventional top-down methods. Here, we use self-assembled systems including granular crystals and onion cells to explore the dynamics of self-assembled media, wherein effects that are negligible at the macroscale, such as adhesion, become significant at microscales and below. Our approach leverages a combination of laser ultrasonic techniques and various computational and analytical modeling techniques drawn from the areas of nonlinear dynamical systems, solid mechanics, and acoustic metamaterials.

Example papers on this topic from our group: 2016 Physcial Review Letters, 2019 Nanoscale, 2021 Applied Materials Today

Tailorable nonlinear constitutive laws via microstructural geometric nonlinearity

Materials with nonlinear constitutive laws have proven effective at spatiotemporally redistributing energy for applications such as impact mitigation. However, previous investigations have been restricted to systems with “fixed” nonlinearities. In this project, utilizing additively manufactured structures, we seek the answers to the following questions: “what is the best nonlinearity for a given application?”, “how does microstructural geometric nonlinearity enable any effective material nonlinearity?”, and “what nonlinear constitutive property enables the translation from a given dynamic input to a desired dynamic output?” Major avenues of answering these questions include optimization studies of the dynamic response of continuum and discrete element models, and topological optimization of microstructure design, supported with mechanical and dynamic testing. As such, we seek to understand the mechanics and dynamics of the interplay of mechanochemistry and microstructure, which will result in the development of a new class of highly adaptive microstructured materials. This project is associated with the UCSD Center for DREAMS.

Example papers on this topic from our group: 2021 Composite Structures, 2023 ArXiv, 2024 Arxiv

Topological mechanics and dynamics

Topology concerns the continuous deformability of geometric objects and features such as connectivity. For example, from a topological perspective a coffee cup with a handle can be considered the same as a donut (one through hole). Here, we study the topology of metamaterial mechancial and dynamical modes, to enable new modes of deformation and energy transmission.

Example papers on this topic from our group: 2023 PNAS, 2023 Nature Communications

Image: William Bennett

Active mechanical metamaterials

Nature has given rise to composite materials that exhibit large adaptability and multifunctional responses to environmental stimuli. Two key elements that are present in many such materials are complex microstructure and chemical reactions that occur in response to mechanical stimuli. Here, we seek to understand the mechanics and dynamics of the interplay of activity and microstructure, toward the goal of enabling new material functionalities.

Example papers on this topic from our group: 2020 Polymer Chemistry, 2020 ACS Applied Polymer Materials, 2023 Materials & Design