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Creators/Authors contains: "Ware, Henry Oliver T."

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  1. Abstract

    This decade has witnessed the tremendous progress in miniaturizing optical imaging systems. Despite the advancements in 3D printing optical lenses at increasingly smaller dimensions, challenges remain in precisely manufacturing the dimensionally compatible optomechanical components and assembling them into a functional imaging system. To tackle this issue, the use of 3D printing to enable digitalized optomechanical component manufacturing, part‐count‐reduction design, and the inclusion of passive alignment features is reported here, all for the ease of system assembly. The key optomechanical components of a penny‐sized accommodating optical microscope are 3D printed in 50 min at a significantly reduced unit cost near $4. By actuating a built‐in voice‐coil motor, its accommodating capability is validated to focus on specimens located at different distances, and a focus‐stacking function is further utilized to greatly extend depth of field. The microscope can be readily customized and rapidly manufactured to respond to task‐specific needs in form factor and optical characteristics.

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  2. Abstract

    3D printing, formally known as additive manufacturing, creates complex geometries via layer‐by‐layer addition of materials. While 3D printing has been historically perceived as the static addition of build layers, 3D printing is now considered as a dynamic assembly process. In this context, here a new 3D printing process is reported that executes full degree‐of‐freedom (DOF) transformation (translating, rotating, and scaling) of each individual building layer while utilizing continuous fabrication techniques. Transforming individual building layers within the sequential layered manufacturing process enables dynamic transformation of the 3D printed parts on‐the‐fly, eliminating the time‐consuming redesign steps. Preserving the locality of the transformation to each layer further enables the discrete conformal transformation, allowing objects such as vascular scaffolds to be optimally fabricated to properly fit within specific patient anatomy obtained from the magnetic resonance imaging (MRI) measurements. Finally, exploiting the freedom to control the orientation of each individual building layer, multimaterials, multiaxis 3D printing capability are further established for integrating functional modules made of dissimilar materials in 3D printed devices. This final capability is demonstrated through 3D printing a soft pneumatic gripper via heterogenous integration of rigid base and soft actuating limbs.

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  3. Abstract

    3D‐printed hydrogel scaffolds functionalized with conductive polymers have demonstrated significant potential in regenerative applications for their structural tunability, physiochemical compatibility, and electroactivity. Controllably generating conductive hydrogels with fine features, however, has proven challenging. Here, micro‐continuous liquid interface production (μCLIP) method is utilized to 3D print poly(2‐hydroxyethyl methacrylate) (pHEMA) hydrogels. With a unique in‐situ polymerization approach, a sulfonated monomer is first incorporated into the hydrogel matrix and subsequently polymerized into a conjugated polyelectrolyte, poly(4‐(2,3‐dihydro‐thieno[3,4‐b][1,4]dioxin‐2‐ylmethoxy)‐butane‐1 sulfonic acid sodium salt (PEDOT‐S). Rod structures are fabricated at different crosslinking levels to investigate PEDOT‐S incorporation and its effect on bulk hydrogel electronic and mechanical properties. After demonstrating that PEDOT‐S does not significantly compromise the structures of the bulk material, pHEMA scaffolds are fabricated via μCLIP with features smaller than 100 µm. Scaffold characterization confirms PEDOT‐S incorporation bolstered conductivity while lowering overall modulus. Finally, C2C12 myoblasts are seeded on PEDOT‐pHEMA structures to verify cytocompatibility and the potential of this material in future regenerative applications. PEDOT‐pHEMA scaffolds promote increased cell viability relative to their non‐conductive counterparts and differentially influence cell organization. Taken together, this study presents a promising new approach for fabricating complex conductive hydrogel structures for regenerative applications.

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  4. Abstract

    Advancements in three‐dimensional (3D) printing technology have the potential to transform the manufacture of customized optical elements, which today relies heavily on time‐consuming and costly polishing and grinding processes. However the inherent speed‐accuracy trade‐off seriously constrains the practical applications of 3D‐printing technology in the optical realm. In addressing this issue, here, a new method featuring a significantly faster fabrication speed, at 24.54 mm3h−1, without compromising the fabrication accuracy required to 3D‐print customized optical components is reported. A high‐speed 3D‐printing process with subvoxel‐scale precision (sub 5 µm) and deep subwavelength (sub 7 nm) surface roughness by employing the projection micro‐stereolithography process and the synergistic effects from grayscale photopolymerization and the meniscus equilibrium post‐curing methods is demonstrated. Fabricating a customized aspheric lens 5 mm in height and 3 mm in diameter is accomplished in four hours. The 3D‐printed singlet aspheric lens demonstrates a maximal imaging resolution of 373.2 lp mm−1with low field distortion less than 0.13% across a 2 mm field of view. This lens is attached onto a cell phone camera and the colorful fine details of a sunset moth's wing and the spot on a weevil's elytra are captured. This work demonstrates the potential of this method to rapidly prototype optical components or systems based on 3D printing.

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