Ryan C. Hayward

Learn More
Self-actuating materials capable of transforming between three-dimensional shapes have applications in areas as diverse as biomedicine, robotics, and tunable micro-optics. We introduce a method of photopatterning polymer films that yields temperature-responsive gel sheets that can transform between a flat state and a prescribed three-dimensional shape. Our(More)
Thin poly(N-isopropylacrylamide) (PNIPAM) hydrogels were allowed to swell under two conditions: as freestanding layers and as substrate-attached layers. Through a combination of particle tracking and defocusing methods, the positions of beads embedded within the gels were monitored over time via fluorescence microscopy, providing a convenient method to(More)
Colorimetric temperature sensors are prepared from photo-crosslinkable polymers by sequentially spin-coating and crosslinking alternating layers of poly(N-isopropylacrylamide) and poly(para-methyl styrene). Layer thicknesses and copolymer chemistries are chosen to provide robust colorimetric temperature sensors that cover nearly the full visible spectrum.
Polymeric microparticles have been widely investigated as platforms for delivery of drugs, vaccines, and imaging contrast agents and are increasingly used in a variety of clinical applications. Microparticles activate the inflammasome complex and induce the processing and secretion of IL-1β, a key innate immune cytokine. Recent work suggests that although(More)
Efforts to understand and engineer cell behavior in mechanically soft environments frequently employ two-dimensional cell culture substrates consisting of thin hydrogel layers with low elastic modulus supported on rigid substrates to facilitate culturing, imaging, and analysis. Here we characterize how an elastic creasing instability of the gel surface may(More)
In a soft elastic film compressed on a stiff substrate, creases nucleate at preexisting defects and grow across the surface of the film like channels. Both nucleation and growth are resisted by the surface energy, which we demonstrate by studying creases for elastomers immersed in several environments--air, water, and an aqueous surfactant solution.(More)
Traditional synthetic substrates and matrices for cell culture have proven to be of only limited utility in efforts to understand and control cell behavior, in large part because they fail to capture the multifarious biochemical, mechanical, geometric and dynamic characteristics of in vivo environments. However, recent advances in materials chemistry and(More)
Self-folding microscale origami patterns are demonstrated in polymer films with control over mountain/valley assignments and fold angles using trilayers of photo-crosslinkable copolymers with a temperature-sensitive hydrogel as the middle layer. The characteristic size scale of the folds W = 30 μm and figure of merit A/ W (2) ≈ 5000, demonstrated here(More)
The structure of a novel molecularly ordered two-dimensional (2D) silicate framework in a surfactant-templated mesophase has been established by using a combination of solid-state nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction, and quantum chemical and empirical force-field modeling. These materials are unusual in their combination of(More)