Modular and programmable material systems drawing from the architecture of skeletal muscle

Abstract

The passive attributes of skeletal muscle "material" often have origins in nanoscale architecture and functionality where geometric frustrations directly influence macroscale mechanical properties. Drawing from concepts of the actomyosin network, this study investigates a modular, architected material system that leverages spatial constraints to generate multiple stable material topologies and to yield large adaptability of material mechanical properties. By exploiting the shearing actions induced on an actomyosin-inspired assembly of modular material constituents, new intriguing material behaviors are cultivated, including strong metastability and energy-releasing state transitions. Experimental, numerical, and analytical studies reveal that such passive attributes can be tailored by geometric constraints imposed on the modular material system. The geometric parameters can also introduce a bias to the deformations, enabling a programmable response. By invoking the spatial constraints and oblique, shear-like motions inherent to skeletal muscle architecture, this research illustrates new potential for architected material systems that exploit locally tunable properties to achieve targeted macroscopic behaviors.

Dome‐Patterned Metamaterial Sheets

“…[62] Despite the very different materials, chemistries, and length scales involved, the individual domes of our soft actuator can also be conceptually viewed as a mechanical analog of the sarcomere units present in the muscular system of vertebrates. [63,64] As in these biological muscles, the mechanism of action of our soft actuator relies on a modular linear architecture capable of generating large deformations through the local relative lengthening enabled by individual domes.…”

Harnessing transition waves to realize deployable structures

“…Effect of input energy, dissipation, and geometric parameters on the wave front. Numerically predicted time at which each joint along the linkage with next-nearest neighbor connections snaps for different (A) Uper/U (2) 0 , (B) µ, (C) d/L, and (D) l (2) 0 /L. In all analyses, d/L = 0.02 unless stated otherwise.…”

“…In all analyses, d/L = 0.02 unless stated otherwise. Theoretically predicted evolution of the time that it takes for the transition wave to reach the last joint, ∆T, as a function of the geometrical parameters d/L and l (2) 0 /L. semicircular shape.…”

“…Guided by this analysis, we then modify our structure and introduce linear springs with stiffness k (2) = 0.74 N/mm and rest length l…”

“…transition wave | multistability | bistable mechanism | deployable structures M ultistability-the property of having multiple stable equilibrium configurations-has recently emerged as a powerful platform to design a wide range of smart structures, including shape-reconfigurable architectures (1)(2)(3)(4), fully elastic and reusable energy-trapping metamaterials (5), soft swimming robots with preprogrammed directional propulsion (6), and deployable solar panels for aerospace applications (7). Interestingly, the range of attainable functionalities can be further expanded when considering networks of elastically coupled multistable building blocks since these support the propagation of transition waves that sequentially switch the elements from one stable configuration to the other (8)(9)(10).…”