Sticky Multicolor Mechanochromic Labels.

Sticky-colored labels are an efficient way to communicate visual information. However, most labels are static. Here, we propose a new category of dynamic sticky labels that change structural colors when stretched.

NIR-vis-UV Light-Responsive High Stress-Generating Polymer Actuators with a Reduced Creep Rate.

Untethered, light-responsive, high-stress-generating actuators based on widely-used commercial polymers are appealing for applications in soft robotics. However, the construction of actuators that are stable and reversibly responsive to low-intensity ultraviolet, visible, and infrared lights remains challenging. Here, transparent, stress-generating actuators are reported based on ultradrawn, ultrahigh molecular weight polyethylene films.

Unravelling humidity-gated, temperature responsive bilayer actuators.

By spraying liquid crystal mixtures onto stretched polyamide 6 (PA6) substrates, dual-responsive heat/humidity bilayer actuators are generated. The oriented PA6 guides the self-organization of the liquid crystal monomers into well-aligned, anisotropic liquid crystal networks. The bilayer responds to changes in the environmental relative humidity, resulting in bending of the actuator with the liquid crystal network inside the curvature.

Liquid Crystal Networks on Thermoplastics: Reprogrammable Photo-Responsive Actuators.

Arbitrary shape (re)programming is appealing for fabricating untethered shape-morphing photo-actuators with intricate configurations and features. We present re-programmable light-responsive thermoplastic actuators with arbitrary initial shapes through spray-coating of polyethylene terephthalate (PET) with an azobenzene-doped light-responsive liquid crystal network (LCN). The initial geometry of the actuator is controlled by thermally shaping and fixing the thermoplastic PET, allowing arbitrary shapes, including origami-like folds and left- and right-handed helicity within a single sample.

Photonic Shape Memory Polymer with Stable Multiple Colors.

A photonic shape memory polymer film that shows large color response (∼155 nm) in a wide temperature range has been fabricated from a semi-interpenetrating network of a cholesteric polymer and poly(benzyl acrylate). The large color response is achieved by mechanical embossing of the photonic film above its broad glass transition temperature. The embossed film, as it recovers to its original shape on heating through the broad thermal transition, exhibits multiple structural colors ranging from blue to orange.

Time-dependent failure of amorphous poly-D,L-lactide: influence of molecular weight.

The specific time-dependent deformation response of amorphous poly(lactic acid) (PLA) is known to lead to rapid failure of these materials in load-bearing situations. We have investigated this phenomenon in uniaxial compression on P(L)DLLA samples with various molecular weights. The experiments revealed a strong dependence of the yield stress on the applied strain rate.

Time-dependent failure of amorphous polylactides in static loading conditions.

Polylactides are commonly praised for their excellent mechanical properties (e.g. a high modulus and yield strength).

Time-dependent mechanical strength of 70/30 Poly(L, DL-lactide): shedding light on the premature failure of degradable spinal cages.

Study Design: In vitro studies on the mechanical strength of 70/30 poly(l,dl-lactic acid) (70/30 PLDLLA) cages.

Objective: To evaluate the effect of loading rate, humidity, temperature, and continuous static loading on the strength of 70/30 PLDLLA, to elucidate the mechanism of premature failure of degradable spinal cages observed in earlier studies.

Summary Of Background Data: Degradable 70/30 PLDLLA cages have been designed to withstand mechanical loads in a goat lumbar spine for at least 6 months.