Abstract: In one aspect, the disclosure relates to free-standing artificial muscles having a polymeric core encased by an elastic spring. The polymeric core can be any two-way shape memory polymer including, but not limited to, a semicrystalline polymer (polybutadiene polymer, a polycaprolactone polymer, a poly(ethylene-co-vinyl acetate)), a rubber, an ionomer, an elastomer, or a gel. In some aspects, the shape memory polymers are crosslinked. In an alternative aspect, the polymeric core is a twisted and coiled polymeric fiber. In other aspects, the polymeric core is reprocessable, remoldable, and/or recyclable. In one aspect, the elastic spring is metallic, ceramic, plastic, or any combination thereof. The stiffnesses or spring rate of the elastic spring and polymeric core, the two-way shape memory effect of the polymeric core, and their geometrical dimensions can be optimized to maximize the actuation strain based on theoretical principles described herein.

Abstract: Shape memory polymers (SMP), methods of making shape memory polymers, and articles including shape memory polymers are provided. The SMPs include thermoset polymer networks formed from an epoxy and a diamine. The SMPs can be in particle form and can be added to other materials while maintaining expansion capabilities. Articles formed from the SMPs can include rebar.