Controlling and reducing the developed region initiated by photoexposure is one of fundamental goals optical lithography. Here, we demonstrate a two-color irradiation scheme whereby initiating species are generated single-photon absorption at wavelength while inhibiting second, independent wavelength. Co-irradiation second thus reduces polymerization rate, delaying gelation material facilitating enhanced spatial control over polymerization. Appropriate overlapping two beams produces...

Abstract Experimental search for high-temperature ferroelectric perovskites is a challenging task due to the vast chemical space and lack of predictive guidelines. Here, we demonstrate two-step machine learning approach guide experiments in x Bi $$[ {{\mathrm{Me}}_y' {\mathrm{Me}}_{(1 - y)}'' } ]$$ <mml:math...

Liquid crystalline elastomers (LCEs) are soft, anisotropic materials that exhibit large shape transformations when subjected to various stimuli. Here we demonstrate a facile approach enhance the out-of-plane work capacity of these by an order magnitude, nearly 20 J/kg. The enhancement in force output is enabled development room temperature polymerizable composition used both prepare individual films, organized via directed self-assembly retain arrays topological defect profiles, as well act...

Sodium bismuth titanate (NBT) ceramics are among the most promising lead-free materials for piezoelectric applications. This work reports crystal structure and phase evolution of NBT Fe-modified (from 0-2 at.$%$ Fe) using synchrotron x-ray diffraction Raman spectroscopy, at both ambient elevated temperatures. The crystallographic results discussed with reference to permittivity thermal depolarization measurements same compositions. Changes in temperature due Fe substitution were detected by...

Orthogonal, sequential "click" reactions were implemented to yield novel polymeric substrates with the ability record holographic data. The base-catalyzed thiol–acrylate Michael reaction was a writable, stage 1 substrate glass transition temperatures (Tg) ranging from 0 −26 °C and rubbery storage moduli (E′) 11.1 0.3 MPa. loosely cross-linked matrix also contained high refractive index monomer 9-(2,3-bis(allyloxy)propyl)-9H-carbazole (BAPC) that did not participate in thiol–Michael but...

High resolution powder x-ray diffraction patterns of Na0.5Bi0.5TiO3 at selected temperatures were examined to compare structural changes with observed piezoelectric thermal depoling temperatures. The do not correlate discrete phase transition temperatures, and therefore, a is the origin depoling. Rather, correlation made an increase in volume fraction material which does obey long-range Cc space group. behavior may be loss ferroelectric order by decreasing proportion or associated...

Materials capable of complex shape changes have broad reaching applications spanning biomimetic devices, componentless actuators, artificial muscles, and haptic displays. Liquid crystal elastomers (LCE) are a class programmable materials which display anisotropic mechanical deformations in response external stimuli. This work details synthetic strategy to quickly efficiently prepare LCEs through the usage chain transfer agents (CTA). The polyacrylate described herein exhibit large,...

Abstract The calcium rare‐earth (RE) silicate oxyapatite, Ca 2 RE 8 (SiO 4 ) 6 O (RE = Yb, Er, Y, Dy, Nd, Gd, and Sm), powders were synthesized by the solid‐state reaction method characterized X‐ray diffraction (XRD), Raman spectroscopy, elemental composition analysis. thermodynamic properties of oxyapatites have been investigated using high‐temperature oxide melt calorimetry in molten 2PbO–B 3 solvent at 805°C. energetics related to ionic substitution on two crystallographic sites, M(1)...

The shape of liquid crystalline elastomers (LCEs) with spatial variation in the director orientation can be transformed by exposure to a stimulus. Here, informed previously reported analytical treatments, we prepare complex spiral patterns imprinted into LCEs and quantify resulting transformation. Quantification stimuli-induced shapes reveals good agreement between predicted experimentally observed curvatures. We conclude this communication reporting design strategy allow LCE films anchored...

Freestanding substrates with high refractive index modulation, good oxygen resistance, and low volume shrinkage are critical in photolithography for the purpose of density data storage, image patterning anticounterfeiting. Herein, we demonstrate a novel paradigm direct holographic via radical-mediated thiol–yne click reaction subsequent to base-catalyzed thiol-Michael addition reaction. With benefit newly synthesized alkyne monomer, 9-(2-((2-(prop-2-yn-1-yloxy)ethyl)thio)ethyl)-9H-carbazole...

Polymeric materials are pervasive in modern society, part attributable to the diverse range of properties that accessible these materials. Polymers can be stiff or soft, dissipative elastic, adhesive nonstick. Localizing polymeric achieved by a number methods, including self-assembly, lithography, 3-d printing. Here, we detail recent advances preparation "pixelated" polymers prepared directed self-assembly liquid crystalline monomers yield cross-linked polymer networks (liquid networks, LCN,...

Liquid crystal elastomers (LCEs) exhibit anisotropic mechanical, thermal, and optical properties. The director orientation within an LCE can be spatially localized into voxels [three-dimensional (3-D) volume elements] via photoalignment surfaces. Here, we prepare nanocomposites in which both the of single-walled carbon nanotube (SWNT) are locally arbitrarily oriented discrete voxels. addition SWNTs increases stiffness direction, yielding a material with 5:1 directional modulus contrast....

A high-performance holographic recording medium was developed based on a unique combination of photoinitiated thiol-ene click chemistry and functional, linear polymers used as binders. Allyl reactive sites were incorporated along the backbone polymer binder to enable facile film casting facilitate cross-linking by photopolymerization monomers that also serve writing in this distinctive approach materials. The allyl content ratio varied maximize control refractive index contrast....

Nematic elastomers dramatically change their shape in response to diverse stimuli including light and heat. In this paper, we provide a systematic framework for the design of complex three dimensional shapes through actuation heterogeneously patterned nematic elastomer sheets. These sheets are composed nonisometric origami building blocks which, when appropriately linked together, can actuate into array faceted shapes. We demonstrate both theoretically experimentally that predicted manner,...

Abstract Liquid crystalline elastomers (LCEs) are widely recognized for their exceptional promise as actuating materials. Here, the comparatively less celebrated but also compelling nonlinear response of these materials to mechanical load is examined. Prior examinations planarly aligned LCEs exhibit unidirectional deformation loads. A methodology presented realize surface‐templated homeotropic orientation in and omnidirectional nonlinearity deformation. Inkjet printing alignment surface...

In this study we report vaporization coefficients for silica, alumina, and molten anorthite gehlenite obtained by continuous weight loss measurements in a thermogravimetric system with tungsten mesh vacuum furnace. Free surface rates are measured using 2.5 mm droplets on Ir-wire loops. Vaporization were converted to partial pressures the Hertz-Knudsen-Langmuir equation. Where possible, equilibrium pressure determined iridium Knudsen cells addition model calculations. Silica alumina exhibit...

Relaxor ferroelectrics exhibit a unique competition between long-range and short-range interactions that can be tuned electrically, which prioritizes these materials in broad range of electro-mechanical energy-conversion technologies, including biomedical imaging electric-charge generators. Here, we demonstrate differential negative piezoresponse by utilizing the relaxor ferroelectrics. The effect was observed over temperature with local spectroscopy unpoled samples, while no when material...

Monomeric mixtures formulated to prepare a liquid crystal polymer network (LCN) or elastomer (LCE) can be "programmed" by surface alignment retain complex and arbitrary spatial distributions of the director orientation upon polymerization. The localized control in given volume (voxel) within these materials is subject intense research, currently motivated prospect distinctive mechanical responses (both active passive). Here, we report on rapid scalable photopatterning method surfaces with...

ABSTRACT Diffusive photopolymers are an area of intense recent materials development, spurred by interest in holographic data storage, display holography, and custom diffractive optical elements, among other applications. This review examines a range photopolymer formulations academic commercial interest, places their design strategies context via quantitative analysis the recording fidelity, maximum refractive index change degree to which they achieve this limit. Finally, is extended...

Ternary compositions based on Bi (B′B″) O 3 – PbTiO ‐type compounds have been investigated for high‐temperature piezoelectric applications. Compositions in the ternary were chosen to be near binary morphotropic phase boundary ( MPB ) composition of BiScO BS PT ). (100− x − y –( Zr 0.5 Zn [(100− BZZ ] with ≤ 7.5. For &gt; 10, Curie temperature T C decreased below 400°C. Dielectric, piezoelectric, and electromechanical properties characterized as a function temperature, frequency, electric...

Abstract Coupons of Hexoloy ® , CVD SiC, and SiO 2 were thermally cycled in a flowing steam atmosphere 90%/10% H O/O at 1426°C order to simulate the water vapor partial pressure turbine environment. The paralinear model for oxidation volatilization is examined condensed version provided that allows extraction ( k p ) l rates from only few measured data points across small time window. Due high Si(OH) 4 (g) volatility rates, scale thickness approached nearly invariant limiting values (~3‐6...