ACS Applied Optical Materials最新文献

{"title":"Better Understanding of the Composite Colored Cholesteric Liquid Crystal Polymer Network Film Prepared through Polymerization-Induced Chiral Dopant Diffusion","authors":"Tingting Wang,&nbsp;Rui Li,&nbsp;Wei Liu*,&nbsp;Yi Li and Yonggang Yang*,&nbsp;","doi":"10.1021/acsaom.5c0005310.1021/acsaom.5c00053","DOIUrl":"https://doi.org/10.1021/acsaom.5c00053https://doi.org/10.1021/acsaom.5c00053","url":null,"abstract":"<p >Cholesteric liquid crystal polymer network (CLCN) patterns featuring double helical pitches are attractive for decoration and anticounterfeiting. Herein, the polyacrylate-based CLCN films with double helical pitches were fabricated utilizing a nonreactive chiral dopant via a two-step photopolymerization approach. At the first step, a cholesteric liquid crystal (CLC) mixture was irradiated using the 365 nm LED lamp with a low light intensity. Based on oxygen inhibition, only the acrylate molecules near the substrate surface were polymerized. This polymerization caused the chiral dopant to diffuse from the bottom to the top section of the CLC mixture. Then, the structure with double helical pitches was formed. The diffusion of the chiral dopant was time-dependent. During the second step, this structure was stabilized following irradiation with a high-pressure Hg lamp (1.0 kW). When the chiral dopant was reactive, the Bragg reflection band of the CLCN film was broadened, which was proposed to be driven by the diffusion of the nematic liquid crystal. Moreover, patterns exhibiting composite structural colors were prepared, with potential applications in decoration.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"989–997 989–997"},"PeriodicalIF":0.0,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring the Efficiency of Photoinduced Electron Transfer at the Perovskite@Metal–Organic Framework Buried Interfaces","authors":"Deejan Debnath,&nbsp;Barnali Saha,&nbsp;Madhusudan Das,&nbsp;Himadri Acharya* and Sujit Kumar Ghosh*,&nbsp;","doi":"10.1021/acsaom.5c0003710.1021/acsaom.5c00037","DOIUrl":"https://doi.org/10.1021/acsaom.5c00037https://doi.org/10.1021/acsaom.5c00037","url":null,"abstract":"<p >Metal halide perovskite nanocrystals exhibit remarkable semiconductor characteristics with continuously tunable optical band gap covering almost all of the visible spectrum that imbue numerous prospective applications, including the field of photocatalysis. The ease of synthesis, significant efficiency of light absorption and emission, and remarkable charge transport characteristics offer many exciting possibilities to unravel the specific physicochemical attributes to ameliorate in a diverse range of niche applications. However, the stability of the perovskite quantum dots (PQDs) in aqueous medium is an important issue, as the naked nanostructures are highly sensitive to environmental conditions. Among the different approaches to engendering the intrinsic stability issue of perovskite nanostructures, the encapsulation of perovskites within the interpenetrating structures of metal–organic frameworks (MOFs) can be alleviated as a viable solution to this problem. We demonstrate the crystallization of CsPbBr₃ QDs within the pore metal–organic frameworks based on earth-abundant elements such as Cr, Fe, and Ti as the matrices and investigated the photocatalytic activities toward the degradation of methyl orange as the model reaction. The CsPbBr₃ QDs within the nanocavities of metal–organic frameworks have been synthesized using a ship-in-bottle strategy and characterized through a series of spectroscopic and microscopic techniques. Upon encapsulation within the pores, the photogenerated electrons of CsPbCl₃ QDs can be transferred to the metal catalytic sites of the MOF structures with a longer carrier lifetime on the nanosecond time scale. The turnover frequency has been calculated as 27, 15, and 22 mol g^–1 h^–1 in the presence of CsPbBr₃@MIL-101-Cr, CsPbBr₃@MIL-101-Fe, and CsPbBr₃@MIL-125-Ti nanohybrids, respectively. The buried heterojunctions formed at the perovskite@MOF nanohybrids decrease the trap density and, thus, increase the mobilities of the electrons and holes that enhance carrier extraction and suppress charge recombination. Therefore, the concept of utilizing the photoinduced electron transfer at the perovskite–MOF interface toward the degradation of organic pollutants could pave an avenue for plausible industrial applications.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"926–941 926–941"},"PeriodicalIF":0.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Template-Mediated Synthesis of Methylammonium Lead Bromide Quantum Nanodots with Tailored Optical Properties","authors":"Pang Chung,&nbsp;Ya-Sen Sun*,&nbsp;Bo-Cheng Zhao and Chia-Liang Liu,&nbsp;","doi":"10.1021/acsaom.5c0003410.1021/acsaom.5c00034","DOIUrl":"https://doi.org/10.1021/acsaom.5c00034https://doi.org/10.1021/acsaom.5c00034","url":null,"abstract":"<p >This research provides critical insights into the role of block copolymers (BCP), salt dissociation/complexation, and coassembly of polymer chains with salt complexes in perovskite nanocrystal synthesis. We demonstrate the formation of hybrid nanostructures using polystyrene-<i>block</i>-poly(ethylene oxide) (PS-<i>b</i>-PEO) as a template for lead bromide (PbBr₂) dissociation and complexation in 1,3,5-trimethylbenzene (TMB) and the encapsulation of MAPbBr₃ quantum nanodots in its cosolvent with methanol. PbBr₂, typically insoluble in TMB, forms [PbBr₃]⁻ and [PbBr₄]^2– complexes in the presence of PS-<i>b</i>-PEO. These complexes bind with the PEO block, coassembling into crystalline intermediates such as irregular nanosheets and polygonal nanoplates studded with tiny nanodots. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and wide-angle X-ray diffraction (WAXD) reveal that these intermediate nanostructures are not orthorhombic PbBr₂ crystals but rather distinct crystals resulting from the coassembly of PS-<i>b</i>-PEO, [PbBr₃]⁻/[PbBr₄]^2– complexes and PbBr₂ nanodots. PS-<i>b</i>-PEO acts as a soft colloidal template, stabilizing the lead halide complexes and preventing their direct precipitation in TMB. However, our findings indicate that to effectively form encapsulated MAPbBr₃ quantum nanodots with narrow size distribution, it is crucial to remove excess PbBr₂ microcrystals, use a low concentration of PS-<i>b</i>-PEO, and add sufficient MABr contents. Otherwise, MAPbBr₃ quantum nanodots tend to coexist with precursor nanostructures or MA₄PbBr₆, which negatively impacts their optical properties. Moreover, high concentrations of PS-<i>b</i>-PEO favor the growth of polygonal nanoplates, which compete with the growth of MAPbBr₃ quantum nanodots.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"908–925 908–925"},"PeriodicalIF":0.0,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsaom.5c00034","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithography-Free Dielectric Etalon on Silicon with Thin GST Semiabsorbing Boundary for Broadband Reflective Color Filtering","authors":"Mandeep Jangra,&nbsp;Anaisha Mehta and Arnab Datta*,&nbsp;","doi":"10.1021/acsaom.5c0005110.1021/acsaom.5c00051","DOIUrl":"https://doi.org/10.1021/acsaom.5c00051https://doi.org/10.1021/acsaom.5c00051","url":null,"abstract":"<p >A reflective broadband color filter based on a bi-interface engineered all-dielectric Fabry–Pérot (FP) etalon structure has been demonstrated here. The filter was fabricated on a p-silicon substrate (p-Si) without needing lithography. First, a wet oxide (spacer) of variable thickness was grown on the p-Si. On the top of the spacer, a germanium–antimony–telluride (Ge₂Sb₂Te₅) semiabsorbing film was deposited which could couple input light to the FP cavity. Through a transfer matrix method (TMM)-based numerical simulation, we found that the underlying p-Si could behave as a back reflector of a FP etalon supporting cavity modes. Hence, no extra metal layer deposition and their etching for defining the reflector pairs of a FP etalon were needed, and a minimum number of dielectric layers were involved. Cavity resonance intensified absorption of the allowed modes, which led to obtaining reflection dips in the filter response as could be controlled by the thicknesses of spacer and the Ge₂Sb₂Te₅ layer and by the angle of incidence of the input excitation and its polarization state. Combined reflectance spectra from the FP etalon resulted in a broadband color gamut with respect to chromaticity, which was different from the spectroscopically pure colors. The all-dielectric FP etalon concept was further utilized to engrave a complex colorful image (World Map) over an approximate 5.2 mm² active area on silicon starting with direct oxidation of the substrate, followed by multiple levels of selective etching.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"969–977 969–977"},"PeriodicalIF":0.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral Shaping by Radiative Energy Transfer in CsPbBr3 Nanocrystal–Dye Mixtures","authors":"Ina Flaucher*,&nbsp;Marco van der Laan,&nbsp;Jef Huisman and Peter Schall*,&nbsp;","doi":"10.1021/acsaom.5c0009810.1021/acsaom.5c00098","DOIUrl":"https://doi.org/10.1021/acsaom.5c00098https://doi.org/10.1021/acsaom.5c00098","url":null,"abstract":"<p >Spectral shaping is a technique to spectrally focus the broadband solar spectrum for diverse energy conversion applications from luminescent solar concentrators to horticulture. Fluorescent dyes have been used as optically active components due to their high photoluminescence quantum yield (PLQY), but their absorption range is limited. Nanocrystals offer broadband absorption but are typically limited in spectral shifting, causing photon recycling. Here, we investigate radiative energy transfer from CsPbBr₃ nanocrystals to Nile Red dye, combining the nanocrystals’ broadband absorption with the dye’s targeted emission. We use experimental transmittance and (time-resolved) photoluminescence (PL) spectroscopy together with photon random walk simulations to show that indeed radiative energy transfer occurs and that the resulting extended absorption range due to the nanocrystals can significantly enhance the spectral conversion efficiency. Experimentally, the energy transfer manifests in PL excitation spectra as strongly enhanced absorption and in time-resolved PL as a prolonged rise and decay time, reflecting the delay due to the extra absorption and emission processes. The photon random walk simulations account for the observed spectra quantitatively and allow prediction of conversion spectra for a wide range of nanocrystal and dye concentrations as well as their material parameters such as the PLQYs of the components. Specifically, we highlight the role of competitive absorption and the importance of taking the spectral intensity profile of excitation light into account when quantifying broadband energy transfer. These results open the door to tuning of absorption and emission spectra via the design of optimized compound mixtures for targeted spectral shaping applications.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"1036–1043 1036–1043"},"PeriodicalIF":0.0,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsaom.5c00098","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoactivated Radiation-Stimulated Luminescence from Scintillator–Silica Disk Pellet for Detecting Tritium β-Particles","authors":"Hirokazu Miyoshi*,&nbsp;Yoko Utsumi and Mami Nakamura,&nbsp;","doi":"10.1021/acsaom.5c0004310.1021/acsaom.5c00043","DOIUrl":"https://doi.org/10.1021/acsaom.5c00043https://doi.org/10.1021/acsaom.5c00043","url":null,"abstract":"<p >Photoactivated radiation-stimulated luminescence (PARSL) from a scintillator–silica disk pellet for detecting β-particles was studied in terms of the pellet structure related to light scattering and trap sites based on excited electron accumulation, and the stimulation of photoactivated ³H β-particles by luminescence was demonstrated. The structure, which had some pores on the disk pellet and its cross section, exhibited excited light scattering on both the surface and inside of the disk pellet, as revealed by scanning electron microscopy and the transmittance of light. The accumulation of electrons excited by light and β-particle irradiations in the trap sites was confirmed by measurements of the thermoluminescence glow curves and emission spectra. The photostimulated luminescence (PSL) from the stored electrons upon β-particle irradiation produced a PSL image. The PARSL from ³H β-particles was demonstrated to be useful for detecting ³H β-particles by pre-light-emitting diode (LED) light irradiation to measure the net count rate, scintillation spectra, and wave-height spectra. The PARSL mechanism was proposed to involve excitation and emission processes. (1) LED light at 365 nm excited scintillator–silica disk pellets, resulting in the emission of fluorescence. (2) Part of the excited electrons were stored at the trap level of the scintillator–silica disk pellets. (3) β-particles stimulated the stored electrons in the trap sites to release luminescence.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"949–958 949–958"},"PeriodicalIF":0.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep Learning-Optimized, Fabrication Error-Tolerant Photonic Crystal Nanobeam Cavities for Scalable On-Chip Diamond Quantum Systems","authors":"Sander van Haagen*,&nbsp;Salahuddin Nur and Ryoichi Ishihara,&nbsp;","doi":"10.1021/acsaom.5c0006010.1021/acsaom.5c00060","DOIUrl":"https://doi.org/10.1021/acsaom.5c00060https://doi.org/10.1021/acsaom.5c00060","url":null,"abstract":"<p >Cavity-enhanced diamond color center qubits can be initialized, manipulated, entangled, and read individually with high fidelity, which makes them ideal for large-scale, modular quantum computers, quantum networks, and distributed quantum sensing systems. However, diamond’s unique material properties pose significant challenges in manufacturing nanophotonic devices, leading to fabrication-induced structural imperfections and inaccuracies in defect implantation, which hinder reproducibility, degrade optical properties and compromise the spatial coupling of color centers to small mode-volume cavities. A cavity design tolerant to fabrication imperfections─such as surface roughness, sidewall slant, and nonoptimal emitter positioning─can improve coupling efficiency while simplifying fabrication. To address this challenge, a deep learning-based optimization methodology is developed to enhance the fabrication error tolerance of nanophotonic devices. Convolutional neural networks (CNNs) are applied to promising designs, such as L2 and fishbone nanobeam cavities, predicting <i>Q</i>-factors at least one-million times faster than traditional finite-difference time-domain (FDTD) simulations, enabling efficient optimization of complex, high-dimensional parameter spaces. The CNNs achieve prediction errors below 3.99% and correlation coefficients up to 0.988. Optimized structures demonstrate a 52% reduction in <i>Q</i>-factor degradation, achieving quality factors of 5 × 10⁴ under real-world conditions and a 2-fold expansion in field distribution, enabling efficient coupling of nonoptimally positioned emitters. Compared to previous deep-learning optimization methods, this approach achieves twice the <i>Q</i>-factor performance in the presence of fabrication errors, significantly enhancing device robustness. Hence, this methodology enables scalable, high-yield manufacturing of robust nanophotonic devices, including the cavity-enhanced diamond quantum systems developed in this study.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"998–1010 998–1010"},"PeriodicalIF":0.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsaom.5c00060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Titanium Dioxide Nanoparticle Suspensions as a Low-Cost Surface Coating to Improve Optical Profilometry of Transparent 3D-Printed Microdevices.","authors":"Ignatius Semmes, Gerard K Lorio, Fannyuy V Kewir, Jorge A Belgodere, William Todd Monroe","doi":"10.1021/acsaom.5c00010","DOIUrl":"https://doi.org/10.1021/acsaom.5c00010","url":null,"abstract":"<p><p>Improved resolution of stereolithography (SLA) 3D printers is accelerating the rapid prototyping of microdevices and has highlighted the need to evaluate their dimensional accuracy. Optical profilometry using structured light allows for rapid 3D scanning of devices with micrometer resolution but requires part surfaces with sufficient opacity and reflectivity for accurate measurement. Microfluidic devices are often made with transparent materials (e.g., clear SLA resins, PDMS, and glass), which poorly reflect the projected light, making them difficult to optically measure. To address the poor reflectivity of transparent objects, a low-cost titanium dioxide (TiO₂) nanoparticle suspension was formulated to coat and opacify the surface of an object using a simple handheld airbrush. PDMS microdevices were cast from SLA printed molds to evaluate part geometry accuracy, surface roughness, and coating thickness between varying concentrations of the custom TiO₂ spray, as well as commercially available 3D scanning sprays. TiO₂ suspensions of 10 and 100 mg/mL in ethanol permitted accurate interrogation of parts of the features, yielding comparable results to commercial treatments. The performance of the treatments on different surface materials and channel designs was analyzed based on their intrinsic properties (roughness, thickness, and carrier solvent). The lower TiO₂ concentration was preferable for microdevices with constricted features due to its lower coating thickness, while the higher concentration was favored for features with smaller z-heights due to its lower coating roughness, highlighting the need for tunable coating formulations. Cost, ease of use, and customization of the surface treatments were compared. The commercial treatments, in both the aerosol canister and microemulsion formats, were more time-effective due to minimal setup and cleaning requirements, whereas the custom TiO₂ coatings were more cost-effective and customizable due to tunable properties and known composition.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"871-880"},"PeriodicalIF":0.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12038832/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144041903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Role of Sm3+ Concentration in Controlling the Structural Stability, Morphology Tunability, Optical Performance, and Luminescent Efficiency of NaLaxSm1–x(MoO4)2 Nanophosphors","authors":"Sahaya Dennish Babu George*,&nbsp;Shafeera Nirathintavida Nittakaran,&nbsp;Judith Jayarani Arockiasamy,&nbsp;Swetha Madamala,&nbsp;Lavanya Narasimman,&nbsp;Sarojini Kuppamuthu and Sahaya Shajan Xavier,&nbsp;","doi":"10.1021/acsaom.5c0007010.1021/acsaom.5c00070","DOIUrl":"https://doi.org/10.1021/acsaom.5c00070https://doi.org/10.1021/acsaom.5c00070","url":null,"abstract":"<p >In this work, a highly effective oleic acid assisted hydrothermal method has been employed for the large-scale synthesis of NaLa<i>_<i>x</i></i>Sm_1–<i>x</i>(MoO₄)₂ (<i>x</i> = 1, 0.75, 0.50, 0.25, and 0) nanophosphors. These nanophosphors crystallize in a pure tetragonal phase, exhibiting a remarkable morphological evolution from spherical nanoparticles to nanoplatelets and nanorice structures. The role of oleic acid as both a capping agent and shape modifier is crucial in tailoring the morphology, thereby influencing the optical properties. Structural and elemental analyses through SEM and TEM confirm the well-defined features and stoichiometric composition of the synthesized materials. Beyond their fascinating structural versatility, these nanophosphors demonstrate intense and tunable luminescence in the visible region, governed by the Sm³⁺ concentration. Under ultraviolet excitation, they emit a strong orange-red light, attributed to the characteristic f–f transitions of Sm³⁺ ions. Photoluminescence analysis further confirms the enhancement in luminescence efficiency, with an optimized Sm³⁺ doping concentration yielding superior quantum efficiency for optoelectronic applications. The ability to modulate the morphology and luminescence properties makes NaLa<i>_<i>x</i></i>Sm_1–<i>x</i>(MoO₄)₂ (<i>x</i> = 1, 0.75, 0.50, 0.25, and 0) nanophosphors highly promising for advanced applications. This work paves the way for multifunctional luminescent materials with tailored properties for cutting-edge photonics, LEDs, security protection, and micronano optical functional device applications.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"1011–1024 1011–1024"},"PeriodicalIF":0.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Titanium Dioxide Nanoparticle Suspensions as a Low-Cost Surface Coating to Improve Optical Profilometry of Transparent 3D-Printed Microdevices","authors":"Ignatius Semmes,&nbsp;Gerard K. Lorio,&nbsp;Fannyuy V. Kewir,&nbsp;Jorge A. Belgodere* and William Todd Monroe*,&nbsp;","doi":"10.1021/acsaom.5c0001010.1021/acsaom.5c00010","DOIUrl":"https://doi.org/10.1021/acsaom.5c00010https://doi.org/10.1021/acsaom.5c00010","url":null,"abstract":"<p >Improved resolution of stereolithography (SLA) 3D printers is accelerating the rapid prototyping of microdevices and has highlighted the need to evaluate their dimensional accuracy. Optical profilometry using structured light allows for rapid 3D scanning of devices with micrometer resolution but requires part surfaces with sufficient opacity and reflectivity for accurate measurement. Microfluidic devices are often made with transparent materials (e.g., clear SLA resins, PDMS, and glass), which poorly reflect the projected light, making them difficult to optically measure. To address the poor reflectivity of transparent objects, a low-cost titanium dioxide (TiO₂) nanoparticle suspension was formulated to coat and opacify the surface of an object using a simple handheld airbrush. PDMS microdevices were cast from SLA printed molds to evaluate part geometry accuracy, surface roughness, and coating thickness between varying concentrations of the custom TiO₂ spray, as well as commercially available 3D scanning sprays. TiO₂ suspensions of 10 and 100 mg/mL in ethanol permitted accurate interrogation of parts of the features, yielding comparable results to commercial treatments. The performance of the treatments on different surface materials and channel designs was analyzed based on their intrinsic properties (roughness, thickness, and carrier solvent). The lower TiO₂ concentration was preferable for microdevices with constricted features due to its lower coating thickness, while the higher concentration was favored for features with smaller z-heights due to its lower coating roughness, highlighting the need for tunable coating formulations. Cost, ease of use, and customization of the surface treatments were compared. The commercial treatments, in both the aerosol canister and microemulsion formats, were more time-effective due to minimal setup and cleaning requirements, whereas the custom TiO₂ coatings were more cost-effective and customizable due to tunable properties and known composition.</p>","PeriodicalId":29803,"journal":{"name":"ACS Applied Optical Materials","volume":"3 4","pages":"871–880 871–880"},"PeriodicalIF":0.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsaom.5c00010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}