Advanced Materials Technologies

Digital micromirror device (DMD)-based bioprinting enables high-resolution fabrication of hydrogel-based tissue constructs, but print fidelity and hydrogel mechanics are typically coupled through polymer concentration, light exposure, and crosslinking density. This creates a materials constraint for vascular bioprinting, where constructs must preserve microscale architecture during fabrication while supporting multicellular remodeling, lumen formation, and long-term tissue organization. To meet these requirements, we developed a 4D GelMA-Cad/gelatin hydrogel with time-dependent mechanics that maintains print fidelity while providing a soft, cell-permissive matrix. GelMA-Cad provides a covalently photocrosslinked, bioactive network containing an N-cadherin-mimetic peptide, while uncrosslinked gelatin serves as a transient matrix-modifying component that diffuses from the hydrogel after fabrication, producing further softening without bulk degradation of the GelMA-Cad network. We characterized hydrogel chemistry with NMR, quantified time-dependent changes in stiffness, visualized pore morphology with cryo-SEM, and evaluated the platform in retinal and pulmonary constructs. The 4D hydrogel supports 3D-patterned accuracy, cell viability, inner blood-retinal barrier vasculature, and vascularized lung-alveolar tissue models. Single-cell RNA-sequencing of the pulmonary vascular-alveolar model demonstrated compartment-specific transcriptional responses, including enrichment of lung capillary-associated endothelial features and AT1-like epithelial states. Overall, this platform decouples DMD print fidelity from post-print matrix mechanics for vascularized soft tissue bioprinting and tissue modeling.

Microfluidics-assisted encapsulation of cells in hydrogel microbeads has found diverse applications in tissue engineering, disease modelling, and drug testing. However, upscaled production of submillimeter-sized microbeads, each encapsulating optimally tens to hundreds of living cells, remains a challenge. Excessive viscous stresses or non-homogeneous crosslinking reactions hamper droplet monodispersity, hydrogel integrity, and/or cell viability. Herein, we present a device consisting of (i) tens of parallel step-emulsifiers arranged radially around the hydrogel inlet and (ii) an in-flow UV crosslinking system capable of continuous generation and crosslinking of up to around 45000 microbeads/min, each encapsulating N~50 cells, at cell viability exceeding 80%. We use gelatin methacryloyl (GelMA) as the biomaterial of choice and establish a unique sweet spot in terms of UV wavelength, irradiance, and exposure time- the latter controlled via the net applied flow rate and the length of the UV-exposed microchannel- at which we achieve an optimal balance between long-term microbead stability and cell viability. In particular, we observe a strong correlation between reduced cell viability and poor crosslinking efficiency, the latter attributed to the presence of a spontaneous core-shell structure. We further study the impact of added methacrylated hyaluronic acid (HAMA) and extracellular matrix (ECM) on cell proliferation and microtissue formation in the case of triple-negative breast cancer (TNBC) cells for future application in drug testing. The upscaled production of the encapsulated microtissues demonstrated here provides new perspectives for both drug testing and cell therapies where the precision in microenvironment formulation as well as production throughput remain of primary importance.

Carbon is a versatile electrode material that is used in applications ranging from electrical energy storage and electrosynthesis to CO2 conversion, H2 production, and biosensing. The development of pyrolytic carbon electrodes derived from lithographically patterned photoresist structures has expanded the possibilities for creating diverse 2D and 3D electrode designs. In this paper, we present disc-shaped SU-8-derived pyrolytic carbon scaffold electrodes with an open hexagonal honeycomb lattice. The scaffolds were fabricated, using embedded 3D printing within a shear-thinning support bath composed of fused silica nanoparticles (7% w/v) in mineral oil. The rheological properties of the support bath were optimized to enable the printing of low-viscosity materials like SU-8, which would otherwise lack structural integrity in standard extrusion-based 3D printing. The SU-8 scaffolds were then pyrolyzed and characterized using SEM, Raman spectroscopy, Energy Dispersive X-ray, X-ray Photoelectron Spectrometry, and Transmission Electron Microscopy, which revealed graphene-like 'microflowers' on its surface. Electrochemical analysis demonstrated excellent electrochemical properties. The functionality of the scaffold electrodes was validated by differentiation of human neural stem cells into dopaminergic neurons on the scaffold surface, followed by real-time detection of dopamine exocytosis upon cell depolarization.

Type II photoinitiators are essential for numerous applications, including advanced 3D printing techniques such as Xolography. Despite offering tunable wavelengths and reaction mechanisms, their limited photoreactivity hinders widespread adoption. Solutions to increase reactivity, particularly in aqueous solutions and in a biocompatible manner, are urgently needed. Here, we report the surprising finding that iodixanol enhances reactivity of type II photoinitiation systems. Supplementing Xolographic print resins with iodixanol increases photoreactivity, which reduces print times and light dosage tenfold, and enables printing of previously unprintable material formulations. Surprisingly, iodixanol supplementation also improves cell viability in a dose-dependent manner, while reducing cell-mediated light scattering. Together, this enables accurate Xolographic printing of highly cell-dense bioresins, which facilitated the biofabrication of engineered living matter with up to 100 M cells mL-1 (>40% cells by volume) with a resolution of ~65 microns. These advances enabled the first demonstration of tissue function in Xolographically-printed materials. Human induced pluripotent stem cell-derived cardiomyocytes were printed into contractile cardiac-like engineered living matter, which exhibited enhanced cell-cell contact and synchronous contractions, confirming tissue level function. As a highly water soluble, cytocompatible, and clinically approved compound, iodixanol therefore represents a valuable and translatable solution to improve the reactivity of type II photoinitiation systems, which enables volumetric biofabrication of highly cell dense living matter. This unlocks a new role for iodixanol in a wide variety of fields including dentistry, chemistry, organic photovoltaics, tissue engineering, and 3D printing.

Gelatin methacrylate (GelMA) hydrogels offer many advantageous properties such as excellent biocompatibility, tunable stiffness, and rapid fabrication, making them attractive materials for neural systems-on-a-chip devices used to study axonal outgrowth in three-dimensional (3D) environments. In this study, we evaluate properties of GelMA hydrogels crosslinked with visible blue light and application of these hydrogels for encapsulation of primary dorsal root ganglion (DRG) explants inside a custom microscale device. We selected low GelMA polymer concentrations of 3 % and 6 % w/v for hydrogel preparation to create soft materials and demonstrate the effect of degree of functionalization (DoF) on stiffness of GelMA in a blue light-induced crosslinking system. Additionally, a decrease in crosslinking efficiency and stiffness of GelMA was observed upon reconstitution of the polymer in DMEM cell culture media compared to PBS. To evaluate the axonal outgrowth, DRG explants were encapsulated in various GelMA formulations and cultured for 7 days. Following incubation, the explants were fixed and immunochemically labelled with anti-beta-III-tubulin antibody. We further describe an application of custom-developed semi-automated image analysis tool together with linear mixed effects modeling to evaluate axonal outgrowth across different GelMA formulations. Among the formulations tested in our study, 3 % GelMA 95 % DoF hydrogels supported the longest neurite outgrowth suggesting that matrix properties influenced neurite extension.

Photovoltaic subretinal prostheses replace the lost photoreceptors in patients blinded by atrophic age-related macular degeneration (AMD) and provide central vision by electrically stimulating the inner retinal neurons. Subretinal debris in geographic atrophy separate the inner nuclear layer from the implant by tens of micrometers, increasing the stimulation threshold and reducing the pattern contrast. Absence of this separating layer in animal models diminishes the accuracy of preclinical testing of the next-generation implants, especially with smaller pixels. We developed three-dimensional biomimetic scaffolds nanoprinted onto photovoltaic arrays to provide a precisely controlled separation between the implants and target neurons in animal models of retinal degeneration. Gap sizes of the scaffolds were adjusted to meet the following requirements: they should allow light penetration to the implant, provide unobstructed flow of electric current, but preclude migration of cells into their 3-D structure. Gaps of 3 m were found to be optimal as they restricted cellular migration and maintained the inner nuclear layer above both planar and pillar electrode arrays. Scaffolds did not measurably alter the photovoltaic response and accurately reproduced the distance dependence of stimulation threshold. Following implantation, the initially fluid-filled intra-scaffold space was progressively filled by cellular matter matching the density of the subretinal debris. This transition is expected to increase resistivity of the scaffold to that of tissue, which was evidenced by concurrently improved grating acuity. These results establish a model of the controlled separation between the implant and the target neurons reproducing the features of subretinal debris in geographic atrophy of human patients, thereby providing a platform for accurate preclinical evaluation of the subretinal implants.

Granular hydrogels, made of jammed soft microparticles, are of great interest for 3D (bio)printing, as they combine ideal rheological properties and extensive modularity, yielding favorable microstructures for tissue engineering. Typically, the yield-stress properties of these materials, which facilitate printability, are defined by the preparation state and the initial particle content of the hydrogel. Here, we propose a granular hydrogel whose yield-stress and, consequently, printability and printed scaffolds shape retention can be controlled not only by the initial weight fraction of particles but also by their stimuli-responsive swelling. The responsive microgels are prepared from poly(N-isopropylacrylamide) crosslinked by dynamic covalent disulfide bonds. The particles swelling is triggered by reduction-induced cleavage of the disulfide bonds into two pendant thiol groups, enabling printing of multilayer scaffolds with high shape fidelity. Without chemically induced swelling, the same formulation requires higher particle concentrations to be printable. Importantly, the printed structures can be annealed by oxidizing the thiol units back into disulfide inter-particle bonds. The printed scaffolds are compatible with human dermal fibroblasts (HDF) and support cell-material interactions. This system offers a unique opportunity for on-demand modulation of both printability and scaffold microstructure, enabling unique control over local stiffness, packing density, and porosity in granular scaffolds.

In breast cancer, collagen fiber alignment and the second harmonic generation forward-to-backward ratio (F/B), an optical measurement sensitive to fibril-scale organization within collagen fibers, have each been associated with metastatic outcome. Although both are measured at the tumor-stromal interface, in vitro studies have largely examined them separately, because experimental systems have not allowed the two to be varied independently. To address this technical gap, we used a microfluidic biofabrication approach to generate paired aligned and unaligned regions within 3D collagen hydrogels via extensional strain and varied measured F/B across gels by changing the pre-gel pH. The resulting library covered alignment values reported in breast tumors and F/B values associated with poorer metastatic outcome in invasive ductal carcinoma at matched matrix stiffness, pore diameter, and fiber fraction. In MDA-MB-231 cells, alignment biased migration along the fiber axis without changing migration speed, as expected, but the magnitude of the contact guidance response varied with measured F/B. In contrast, MCF-7 cells showed little overall contact guidance, yet migrated ~30% faster in high F/B than low F/B gels in both aligned and unaligned regions. Together, these results show that cells migrated differently in matrices with similar fiber alignment. Thus, including measured F/B may provide additional information to help anticipate how cells migrate in collagen environments that appear similar based on alignment alone.

Hormone dynamics are central to a multitude of conditions in women's health; however, limitations in the cost, convenience, and multiplexing capacity of current hormone assays preclude routine longitudinal hormone testing. This limitation severely restricts our understanding in this historically neglected field, presenting a need for improved bioanalytical tools to support hormone-informed care. Silicon photonic resonator sensors have excellent multiplexing capacity and scalable fabrication, and offer strong potential to meet this important need. Here we demonstrate, for the first time, multiplexed silicon photonic detection of two urinary hormone biomarkers, follicle-stimulating hormone (FSH) and pregnanediol-3-glucuronide (PdG), using sub-wavelength grating ring resonators and a polydopamine-based, regenerable surface chemistry. We combine a sandwich immunoassay for FSH and an antigen-down competitive immunoassay for PdG on the same chip, both amplified using a commercially available quantum-dot-streptavidin conjugate and with on-chip regeneration over multiple measurement cycles. In artificial urine, this proof-of-principle multiplexed assay achieves limits of detection of 0.594 ng/mL for FSH and 19.1 ng/mL for PdG. This architecture is inherently scalable to tens of hormone targets on a millimetre-scale chip (a >10x multiplexing improvement over typical lateral-flow immunoassays) enabling future low-cost, quantitative at-home hormone panels that could transform research, diagnostics, and treatment in women's health.

Microlasers based on whispering-gallery modes (WGMs) provide bright, spectrally narrow emission, making them ideal optical probes for high-resolution cellular tagging, single-cell tracking, and biosensing. To reproducibly apply WGM microlasers in biomedical or tissue-engineering contexts, control over the number of lasers in a cell population is highly desirable. Here we use a commercial instrument for flow cytometry-based cell sorting to obtain HEK293T cell populations with a controlled number of polystyrene laser particles (LPs). By modifying the particle surface with poly(ethyleneimine) (PEI) or lipofectamine, we enhance LP-association to cells. We demonstrate that our sorting procedure yields viable cells showing unchanged proliferation rates. Manufacturer-dependent differences in particle-cell interactions were observed and investigated by scanning and transmission electron microscopy (SEM/TEM) and flow cytometry. Finally, we show that the same sorting approach enables the generation of multi-cellular spheroids with a defined ratio of LP-containing and LP-free cells. This work lays the foundation for larger tissue engineering studies with defined LP populations and control over LP-placement with respect to the cell.

A major challenge in vascular tissue engineering is the development of scalable fabrication methods capable of producing vascular grafts with suitable mechanical properties and hemocompatibility for both preclinical evaluation and future clinical translation. Using a recently developed method to generate acellular vascular grafts from densified collagen hydrogel, we present a proof-of-concept in vivo evaluation of the scalable collagen graft technology. Thick-walled, genipin-crosslinked grafts, representative of a fabrication approach applicable to clinically relevant vessel sizes, were implanted as interposition grafts in the rat abdominal aorta. These grafts supported rapid neointima formation and re-endothelialisation of the luminal surface but developed late thrombosis, highlighting the challenges of evaluating clinically scalable grafts in small-animal models. To enable assessment of the platform in millimetre-scale vessels, we developed a thin-walled (~100 {micro}m), non-crosslinked graft using a constrained densification approach and hyaluronic acid-mediated modulation of collagen fibril assembly to improve compliance matching and hemocompatibility, with the latter providing a matrix-level approach that may complement surface-bound antithrombotic coatings. These grafts remained patent for up to 17 weeks and exhibited neointima formation, re-endothelialisation, and early cellular infiltration into the graft wall. Together, these findings demonstrate in vivo functionality of densified collagen vascular grafts and establish a foundation for future evaluation in larger animal models.

Developing biomaterials that faithfully recapitulate the complex architecture of native tissues is central to tissue engineering. Conventional hydrogels typically exhibit nanoscale porosity, which limits mass transport and cell migration and thereby constrains tissue development. Here, we exploit liquid-liquid phase separation (LLPS) to generate interconnected macroporous gelatin methacryloyl (GelMA) scaffolds with tunable pore sizes ranging from 2 to 50 m under physiological pH conditions. By mapping the GelMA/dextran phase diagram, we identify a composition range in which LLPS occurs through spinodal decomposition, resulting in a spontaneous bicontinuous, trabecular-like architecture. Pore size can be further tuned by varying polymer concentrations and temperature. We advantageously combined thermal gradients and photopatterning to enable spatial control over pore morphology to fabricate hierarchically structured materials. The biological relevance of these architectures is assessed using fibroblasts cultured within controlled porosity gradients. We show that pore size strongly influences cell infiltration, growth, and spatial organization, with larger pores providing sufficient space for cell migration while reducing the dependence on matrix degradation. Pore size of 7-15 m is identified for maximizing fibroblast growth. Overall, our approach provides a versatile platform for porosity screening, enabling the engineering of biomimetic hydrogels with optimized microarchitectures tailored to specific biological contexts for three-dimensional cell culture.

Continuous biomarker monitoring with affinity biosensors remains limited by probe saturation, slow dissociation, signal carryover, and regeneration methods that require chemical washing, harsh buffers, or external reset modules. Here, we report a flow-programmed, self-regenerative electrochemical aptamer-based biosensor for continuous 17{beta}-estradiol monitoring. The platform restores the sensing interface by tuning buffer flow through the device, enabling repeated sensing-regeneration cycles without chemical stripping or active-reset hardware. The biosensor achieves a 1.46 pM limit of detection, and a log-linear dynamic range from 100 pM to 1 M in real human sweat, covering physiologically relevant estradiol concentrations. It exhibits high selectivity, with responses to potential molecularly similar interferents remaining below 10% of the 17{beta}-estradiol signal. Under dynamic flow operation, the device shows reversible signal recovery and stable electrochemical performance, with higher buffer-wash flow reducing baseline carryover between measurements. A coupled binding-transport simulation captures the flow-dependent regeneration trends and maps how wash-flow rate, wash duration, and apparent aptamer affinity affect regeneration efficiency. Ex vivo testing in real human sweat, including samples from pregnant women, supports translational relevance. This work establishes buffer-flow programming as a reagent-free route to regenerable electrochemical aptamer sensing for automated, wearable-compatible estradiol monitoring.

Oxygen (O2) transport is a major limitation in high-density cell culture, particularly as three-dimensional (3D) spheroids are increasingly used to better mimic in vivo tissue environments. Here, we developed a poly(4-methyl-1-pentene) (PMP)-based microwell platform, leveraging its lower molecular absorption and greater mechanical stability than the commonly used O2-permeable polydimethylsiloxane (PDMS), while retaining high O2 permeability. We measured O2 permeability in 50-m-thick PMP membranes and found approximately 200-fold greater O2 permeability than the conventional 1-mm polystyrene culture-plate material. PMP membrane-based microwell plates with 350-m-diameter wells maintained spatial separation of pre-formed hepatocyte spheroids while supplying O2 from the plate bottom, synergistically enhancing spheroid oxygenation. Compared with non-O2-permeable plates, the platform reduced localized hypoxia and hypoxia-associated cell injury while improving spheroid viability and growth. Collectively, PMP-based O2-permeable microwell plates provide a promising, scalable, high-throughput platform for spheroid culture with multiple applications in tissue engineering, drug screening and beyond.

Fermentation is a process through which microorganisms are used to transform basic molecules into high value substances in various applications such as biopharma, food production, and biofuel generation. In such processes, monitoring the health of microbial cells is essential, as it is a key factor in the final product yield. Traditional methods of assessing the health of fermenter populations have involved manually extracting samples from the fermenter for benchtop testing, which lacked the accuracy and efficacy of real-time continuous measurements. This has opened the door for inline sensors to be integrated into fermenters for continuous measurement; including microfluidic based Electrochemical Impedance Spectroscopy (EIS). EIS utilizes a range of frequencies to gain insight into the characteristics of microbial populations, such as cell size and membrane capacitance. EIS cytometry, in particular, has emerged as a relevant tool, as it enables single-cell level detection in real-time. However, current EIS cytometry devices cannot be deployed directly within fermenters due to the high cell density conditions. This has limited EIS analysis in fermenters to bulk measurements averaged across a population. Here, we present a microfluidic chip that uses passive cell-flux-partitioning geometry to direct cells from high-density culture through a single-cell-constrained flow path containing integrated impedance-sensing electrodes. The proposed chip combines geometric channel design and embedded electrodes to enable continuous impedance measurements from cell-containing flow while operating at input cell densities on the scale of 10^9 CFU/mL. This work demonstrates a first step toward integrating single-cell-constrained microfluidic handling with impedance sensing for inline monitoring in industrial biomanufacturing.

Macromolecular release from synthetic cells often relies on membrane pores or channels. We explored whether internally generated osmotic stress could increase membrane permeability and promote release. Using double-emulsion microfluidics, we encapsulated an Escherichia coli cell-free expression system in Pluronic L121 polymersomes to co-express the fluorescent protein mScarlet3 and the dextranase PsDex1711 in the presence of dextran. PsDex1711-mediated dextran hydrolysis produced a greater increase in bulk osmolality than reactions without PsDex1711 DNA. Tracking hundreds of individual polymersomes showed that PsDex1711-containing populations expanded, whereas control populations contracted. The distribution of normalized fluorescence revealed a subset with lower residual fluorescence than the main population. In selected expanded polymersomes, integrated internal mScarlet3 fluorescence declined to 18-22% of peak levels, without visible membrane disruption, consistent with protein release. These findings support a proof of concept for using internal gene expression to promote macromolecular release through osmotic actuation without introducing dedicated membrane pores.

The human pancreas secretes digestive fluid that flows through an extensive ductal network before emptying into the duodenum. However, little is known about how hydrodynamic forces influence pancreatic function and development. We hypothesized that pancreatic cells respond to physiological levels of fluid shear stress. In this study, we developed a microfluidic system featuring reversible sealing between the device layer and the cell culture substrate, enabling (1) conventional open-well cell culture prior to fluid shear stress application and (2) selective patterning of proteins and cells for migration studies. Channel dimensions were chosen to support 24-hour perfusion using standard syringe pumps. Using this platform, we investigated effects of physiological shear stress levels representing basal and activated pancreatic function (2, 8 and 33 mPa) on human iPSC-derived pancreatic progenitor cells. Pancreatic progenitor cells exhibit graded sensitivity to shear stress at the transcriptomic level. Specifically, shear stress upregulated expression of cell cycle-related gene sets; endocrine-associated genes including NEUROG3; and Notch receptor ligands (DLL1, DLL3) in a magnitude-dependent manner. The exposure to unidirectional fluid flow also resulted in a reduction in YAP1 protein content, decreased WWTR1 gene expression, and downregulation of YAP/TAZ target genes. Furthermore, barrier-based migration assays under shear stress revealed that cell patches expanded their boundaries both along and against the flow, with greater distance in the direction of flow. Our system and findings may help lay the foundation for understanding biophysical regulation of developmental processes in a physiologically important, yet hard-to-access, epithelial model system.

Lymphatic endothelial cell (LEC) function is strongly tied to transitions between button- and zipper-like junctions that control fluid flow into vessels. Published methods quantifying junction morphology are limited to single cell analysis or use few quantitative metrics to describe junctions across LEC monolayers. Therefore, a novel 3-step image analysis pipeline was developed to identify new metrics that quantify differences in button- and zipper-like junctions in LECs. The pipeline used Cellpose, CellProfiler, and Fiji to analyze VE-cadherin expression across lymphatic vessels within a 3D microfluidic chip and quantify VE-cadherin radial intensity, number of objects, object size, branchpoints, end-points, and junction thickness. Tumor necrosis factor (TNF)- exposure produced but-ton-like junctions, and unexposed cells were zippered. Radial intensity was heightened at the cell membrane in zipper-like junctions while perinuclear intensity increased for but-ton-like junctions. Increased branchpoints, endpoints, objects per cell, and junction thick-ness were associated with junction buttoning, while increased object size was associated with junction zippering. Principle component analysis results reinforced these trends and identified metric combinations that represented each junctional state. Overall, this semi-automated pipeline quantified differences in VE-cadherin junction morphology across LEC monolayers and generated new quantitative metrics to expand the tools available for studying junction morphology in lymphatic vasculature.

Paper-based colorimetric sensors offer a low-cost and accessible platform for point-of-care (POC) analysis, but enzyme activity loss during coating and drying can weaken analytical signals and require high enzyme loadings or complex immobilization procedures. Although surfactants are widely used to improve wettability in paper-based assays, their potential contribution to colorimetric performance beyond these effects remains unclear. Here, we investigated surfactant-assisted colorimetric signal enhancement in a glucose assay implemented on a 96-puddle paper plate (96-PPP) and identified Tween 20 as the most effective surfactant. Its effect on detection performance became more pronounced as glucose oxidase (GOx) loading decreased; at 0.1 mg/mL GOx, Tween 20 lowered the limit of detection (LoD) from 0.113 to 0.034 mg/mL (approximately 3.3-fold) over a working range of 0-5 mg/mL, despite no statistically significant change in the measured contact angle at this loading. Tween 20 had no appreciable effect on the reaction in solution but preserved 95% of the apparent reaction rate constant after drying, compared with 11% without it, and atomic force microscopy (AFM) revealed a more dispersed dried enzyme morphology on mica. Tween 20-containing sensors also showed slower signal decay during repeated wetting-drying cycles and thermal stress, retained 77% (vs 26%) of the response at 400 mM NaCl, and exhibited within-PPP and between-batch coefficients of variation (CVs) below 10% (vs 12.3-19.5%), while maintaining glucose selectivity over potentially interfering molecules. These results indicate that Tween 20 enhances paper-based glucose sensing beyond wettability, in part by retaining enzyme cascade activity during drying, although the contributions of the individual enzymes and the underlying mechanism remain to be established.

Cell fusion enables cell-based applications, yet systematic optimization remains constrained by low throughput (microfluidic devices) and manual operation (bulk protocols). Here, an automated microfluidic platform is presented for cell pairing and chemical fusion at a statistically relevant scale. High throughput is achieved by arranging ~350,000 deformability-based cell traps as concentric circular arrays in a radial chip. Using tumor and dendritic cells as a model for cancer vaccine, the device reproducibly co-occupies ~75% of traps (~250,000) of which ~140,000 hold exactly one cell of each type. This exceeds the yield of previously reported in hydrodynamic pairing arrays by more than an order of magnitude. A concentration step-up-and-down PEG profile yielded a fusion efficiency of ~20% (range 17.7-23.4%, n =3) at viability above 90% that results in producing at least ~50,000 hybrids per chip. This efficiency is comparable to that reported for PEG-based fusion in small-scale microfluidic devices but obtained at higher throughput and approximately four-fold higher than the conventional benchtop protocol. Fusion efficiencies were quantified by image analysis and validated by flow cytometry. By combining automation, large-area circular trap arrays and reagent control, the platform is useful for data-rich optimization of cell engineering processes previously constrained by limited microfluidic throughput.