arXiv subjects

Ezra Ben-Abu

Publications and source records attributed to Ezra Ben-Abu.

3 recordsLinked to original sources

arXiv2026

Autonomous thermodynamic cycles via robotic mobility and sensing

Thermodynamic cycles are the foundation of energy conversion across natural and engineered systems, transforming heat into useful work. However, these cycles traditionally operate between fixed thermal reservoirs, restricting them to specific locations and temperature differences. Here, we introduce autonomous thermodynamic cycles enabled by robotic mobility and sensing, allowing robots to perform thermodynamic cycles by accessing spatially varying temperature fields. We experimentally realize this concept using multistable gas-filled capsules that circulate within the system across a thermal gradient. Our model reveals that rapid transitions in the capsules' energy states allow the system to operate as a mobile heat engine that harvests and stores energy. By linking the capsule-scale internal energy dynamics to the robot's large-scale navigation strategy, we optimize locomotion paths that balance motion cost and energy harvesting. These findings demonstrate that thermodynamic cycles can emerge when autonomous systems navigate their environments, offering an artificial analog of organisms that forage for energy across spatial resources.

cond-mat.soft↗

arXiv2026

Beyond Crease Geometry: Multistability in Origami-Inspired Structures through Local Fold Architectures

Origami-inspired tubular structures provide a versatile platform for shape morphing, with multistability achieved predominantly through crease-network geometry. Expanding the range of morphing behaviors can therefore require increasingly intricate crease patterns that become more difficult to model and fabricate, ultimately constraining the realizable morphing landscape. Here, we expand the design space of origami-inspired structures beyond geometry by introducing localized instabilities within the crease network, thereby creating compliant multistable structures whose local fold architectures govern global deformation and stability through both constitutive mechanics and geometric constraints. To relate local fold architectures to global multistability, we develop and experimentally validate a modeling framework in which compliant folds are represented as continuous fields that capture spatially varying bistable mechanics. Force- and displacement-controlled design maps demonstrate that global deformation and stability can be programmed through the fold architecture's local parameters. Redistributing bistability within a fixed crease-network topology shifts the global response between compliant, spatially distributed deformation in semi-bistable architectures and discrete transitions within a hierarchically organized space of stable configurations in fully bistable architectures. These results establish a local-to-global design principle for programming both the stable configurations of a structure and the transition pathways connecting them, expanding the design space for multistable metamaterials, adaptive morphing structures, and soft robotic systems.

cond-mat.soft↗

arXiv2025

Magnetic control of metafluids for fluid-like applications of metamaterials

Metamaterials are structures composed of repeating unit-cells which enable macro-scale properties not found in nature. Since metamaterials are typically solid structures with predetermined interconnections, it is challenging to leverage their unique properties for many critical applications that require fluid-like behavior, such as heat engines or cooling cycles. Recent research suggested overcoming this limitation by creating a mechanical metafluid', which is a lubricated suspension of multistable unit-cells. However, realization of this concept necessitates the ability to control both velocity and state of the metafluid. Here, we propose the use of time-varying magnetic fields as a mechanism to manipulate metafluids. We focus on a lattice of magnetic multistable capsules enclosing gas and suspended within a liquid-filled tube. We derive the governing equations and examine one-dimensional fluid mechanics of the metafluid, both theoretically and experimentally, at the viscous limit under magnetic actuation. By applying time-varying magnetic fields, we control both the local compression and expansion of the capsules, as well as the entire flow field. Our theoretical results are compared with experimental data, showing good agreement. This work paves the way for the utilization of mechanical metamaterials to applications that require fluid-like behavior, thus extending the scope of metamaterial applications.

physics.flu-dyn↗