Soft Lithography Research Articles

Personalized Machine Learning-Coupled Nanopillar Triboelectric Pulse Sensor for Cuffless Blood Pressure Continuous Monitoring.

A wearable system that can continuously track the fluctuation of blood pressure (BP) based on pulse signals is highly desirable for the treatments of cardiovascular diseases, yet the sensitivity, reliability, and accuracy remain challenging. Since the correlations of pulse waveforms to BP are highly individualized due to the diversity of the patients' physiological characteristics, wearable sensors based on universal designs and algorithms often fail to derive BP accurately when applied on individual patients. Herein, a wearable triboelectric pulse sensor based on a biomimetic nanopillar layer was developed and coupled with Personalized Machine Learning (ML) to provide accurate and continuous monitoring of BP. Flexible conductive nanopillars as the triboelectric layer were fabricated through soft lithography replication of a cicada wing, which could effectively enhance the sensor's output performance to detect weak signal characteristics of pulse waveform for BP derivation. The sensors were coupled with a personalized Partial Least-Squares Regression (PLSR) ML to derive unknown BP based on individual pulse characteristics with reasonable accuracy, avoiding the issue of individual variability that was encountered by General PLSR ML or formula algorithms. The cuffless and intelligent design endow this ML-sensor as a highly promising platform for the care and treatments of hypertensive patients.

Large-period plasmonic grating with sinusoidal profile for monitoring water quality with high sensitivity

Subwavelength-thick modulation of surface profile of a dielectric layer combined with a nanometer-thick metallic coating on it can be used for highly sensitive refractive index sensing using the concept of surface plasmon resonance. The performance efficiency of a 1D sinusoidal plasmonic grating of higher periodicity made of polymethylmethacrylate with gold coating on it is evaluated for monitoring water quality. The sinusoidal structure is fabricated by the cost-effective soft imprint lithography technique using a commercially available compact disk as master. Even though the master has a step profile, the solution-based technique aids in achieving the sinusoidal profile. The higher periodicity aids in attaining a higher sensitivity of 1533 nm/RIU at normal incidence and also provides a broad wavelength detection regime that can be controlled by the incidence angle. As the sinusoidal grating supports only the fundamental mode of the surface plasmon, it allows for more precise detection of any analyte. The optimized parameters for the structure are obtained through finite element method calculation.

Novel RBC Adhesion and Deformability Assays Reveal Deleterious Effect of Diabetes on RBC Health

Diabetes is one of the most important health issues in the world. The number of people living with diabetes has quadrupled since 1980 1. Cardiovascular disease (CVD), mainly coronary and artery disease, remains the most common cause for morbidity and mortality in people living with diabetes 2,3. A better understanding of the effect of diabetes on the deformability and adhesiveness of red blood cells (RBCs) is essential in assessing disease status and evaluating the risk of CVD, as well as in investigating the effectiveness of potential therapies 4-6. In this work we investigate the deformability of RBCs and their adhesion to erythrocytes using two proprietary microfluidic assays, OcclusionChip 7 and Adhesion Biochip 8 respectively. We previously developed these assays for investigating RBC properties. Occlusion chip assay, consisting of micropillar arrays ranging from 20 µm spacing to 4 µm spacing along the flow direction, creating a gradient of microcapillaries, were fabricated using soft lithography and perfused with isolated RBCs at a constant inlet pressure. Venous samples from diabetic or non-diabetic individuals were collected in EDTA tubes and tested within 48 hours of collection. RBCs were isolated from whole blood and resuspended in PBS at 20% hematocrit, then flown through the chip using a pressure pump for 20 min. The microchannel was then washed and imaged using an inverted microscope. The cells trapped within the micropillar arrays were manually counted to calculate the occlusion index, which we previously established as a biomarker for cell deformability 9. To quantify RBC adhesion to endothelial cells, human umbilical vein endothelial cells (HUVECs) were cultured within a microfluidic channel under flow for 48 h. HUVECs were then activated by heme at a concentration of 40 µM for 1 h at 37 °C. Isolated RBCs resuspended in basal cell culture medium at 20% hematocrit supplemented by 10 mM of HEPES were injected in the microchannel for 15 min. Non-adherent RBCs were rinsed with a basal cell culture medium containing HEPES. The remaining adherent erythrocytes were imaged using an inverted microscope and manually quantified. Our results show that RBCs isolated from individuals with diabetes (A1c > 6.5%) tend to form more occlusion events (OI) than RBCs collected from healthy individuals (A1c < 5.7%), reflecting a loss of deformability (Fig. 1). For comparison we evaluated the elongation index (EI) using ektacytometry (data not shown), and no statistically significant difference was observed. Moreover, RBCs with diabetes tend to be more adhesive to the endothelium than those from healthy individuals, as evident from the count of adherent RBCs (Fig. 2). In conclusion, our assays revealed that diabetes presents a significant adverse effect on the deformability and adhesion of RBCs. These assays provide a much-needed tool for the quantification of these effects for the assessment of CVD risk and the evaluation of treatment efficacy. Future work will focus on conducting a larger-scale study to confirm our preliminary results. We will test samples from patients in all clinically relevant ranges of disease status, i.e. healthy, pre-diabetes, and diabetes.

Replicated biopolymer pattern on PLLA-Ag basis with an excellent antibacterial response

The design of functional micro or nanostructured surfaces is undergoing extensive research for their intriguing multifunctional properties and for large variety of potential applications in biomedical field (tissue engineering or cell adhesion), electronics, optics or microfluidics. Such nanosized topographies can be easily fabricated by various lithography techniques and can be also further reinforced by synergic effect by combining aforementioned structures along materials with already outstanding antibacterial properties. In this work we fabricated novel micro/nanostructured substrates using soft lithography replication method and subsequent thermal nanoimprint lithography method, creating nanostructured films based on poly (l-lactic acid) (PLLA) fortified by thin silver films deposited by PVD. Main nanoscale patterns were fabricated by replicating surface patterns of optical discs (CDs and DVDs), which proved to be easy, fast and inexpensive method for creating relatively large area patterned surfaces. Their antimicrobial activity was examined in vitro against the bacteria Escherichia coli and Staphylococcus epidermidis strains. The results demonstrated that nanopatterned films actually improved the conditions for bacterial growth compared to pristine PLLA films, the novelty is based on formation of Ag nanoparticles on the surface/and in bulk, while silver nanoparticle enhanced and nanopatterned films exhibited excellent antibacterial activity against both bacterial strains, with circa 80 % efficacy in 4 h and complete bactericidal effect in span of 24 h.

Charge-controlled swelling gradients at 200-µm resolution in an open-porous polymeric structure for compliance modulation

Plants combine active and passive liquid-mediated mechanisms across broad spatial and temporal scales, inspiring technological developments, in particular involving variable stiffness. Swelling is of particular interest due to the abundance of plant models and applicable (bio)materials, yet existing control by environmental humidity sorption limits its applications. This work combined swellable polymeric structures with electroactive control: we considered an open-porous polymeric laminate that hosted an electrokinetic medium also co-acting as a swelling agent for the same polymer. A constant volume of liquid (an electrolytic solution) was electrokinetically pumped between the symmetrical laminate’s interior and surface layers: as the second moment of inertia increases from the centre to the surface, the pumping of liquid towards the surface decreases the laminate’s bending stiffness, and vice versa. Ion electrosorption on high-specific-surface-area carbon electrodes, deposited in three layers in the laminate by simple additive spraying, facilitated the ion current necessary for the electrokinetic pumping. Flexural rigidity of the 400 µm thick laminate varied by 7% in response to 2-V input, evidencing swelling gradients forming at half-laminate (i.e., 200-µm) resolution. Charge-driven local rearrangement of liquid allows for broader adoption of bioinspired (and biological) porous architectures, where the channels are defined collectively, not individually as in, e.g., soft lithography. Sub-mm resolution and low-voltage control of liquid offer a high level of integration at minimal assembly, positioning active swelling as a promising solution for wearable and bioinspired soft robotic applications.

A Microlens Array Grating for Miniature Multi-Channel Spectrometers.

Most existing multi-channel spectrometers are constructed by physically stacking single-channel spectrometers, resulting in their large size, high weight, and limited number of channels. Therefore, their miniaturization is urgently needed. In this paper, a microlens array grating is designed for miniature multi-channel spectrometers. A transmissive element integrating microlens arrays and gratings, the MLAG, enables simultaneous focusing and dispersion. Using soft lithography, the MLAG was fabricated with a deviation of less than 2.2%. The dimensions are 10 mm × 10 mm × 4 mm with over 2000 available units. The MLAG spectrometer operates in the 400-700 nm wavelength range with a resolution of 6 nm. Additionally, the designed MLAG multi-channel spectrometer is experimentally verified to have independently valid cells that can be used in multichannel spectrometers. The wavelength position repeatability deviation of each cell is about 0.5 nm, and the repeatability of displacement measurements by the chromatic confocal sensor with the designed MLAG multi-channel spectrometer is less than 0.5 μm.

Micro/nano-patterns for enhancing differentiation of human neural stem cells and fabrication of nerve conduits via soft lithography and 3D printing

Topographical cues on materials can manipulate cellular fate, particularly for neural cells that respond well to such cues. Utilizing biomaterial surfaces with topographical features can effectively influence neuronal differentiation and promote neurite outgrowth. This is crucial for improving the regeneration of damaged neural tissue after injury. Here, we utilized groove patterns to create neural conduits that promote neural differentiation and axonal growth. We investigated the differentiation of human neural stem cells (NSCs) on silicon dioxide groove patterns with varying height-to-width/spacing ratios. We hypothesize that NSCs can sense the microgrooves with nanoscale depth on different aspect ratio substrates and exhibit different morphologies and differentiation fate. A comprehensive approach was employed, analyzing cell morphology, neurite length, and cell-specific markers. These aspects provided insights into the behavior of the investigated NSCs and their response to the topographical cues. Three groove-pattern models were designed with varying height-to-width/spacing ratios of 80, 42, and 30 for groove pattern widths of 1 μm, 5 μm, and 10 μm and nanoheights of 80 nm, 210 nm, and 280 nm. Smaller groove patterns led to longer neurites and more effective differentiation towards neurons, whereas larger patterns promoted multidimensional differentiation towards both neurons and glia. We transferred these cues onto patterned polycaprolactone (PCL) and PCL-graphene oxide (PCL-GO) composite ‘stamps’ using simple soft lithography and reproducible extrusion 3D printing methods. The patterned scaffolds elicited a response from NSCs comparable to that of silicon dioxide groove patterns. The smallest pattern stimulated the highest neurite outgrowth, while the middle-sized grooves of PCL-GO induced effective synaptogenesis. We demonstrated the potential for such structures to be wrapped into tubes and used as grafts for peripheral nerve regeneration. Grooved PCL and PCL-GO conduits could be a promising alternative to nerve grafting.

Assessment of Polydopamine to Reduce Streptococcus mutans Adhesion to a Dental Polymer.

Bacterial adhesion to the surface of materials is the first step in biofilm formation, which will lead to conditions that may compromise the health status of patients. Recently, polydopamine (PDA) has been proposed as an antibacterial material. Therefore, the objective of the current work was to assess and compare the adhesion of Streptococcus mutans to the surface of poly(methyl methacrylate) (PMMA) discs that were modified using PDA following a biomimetic approach versus smooth PDA-coated PMMA surfaces. In addition, an assessment of the growth inhibition by PDA was performed. PMMA discs were manufactured and polished; soft lithography, using the topography from the Crocosmia aurea leaf, was used to modify their surface. PDA was used to smooth-coat PMMA discs by dip-coating. The growth inhibition was measured using an inhibition halo. The surfaces were characterized by means of atomic force microscopy (AFM), the contact angle (CA), and Fourier-transform infrared spectroscopy (FTIR). Polydopamine exhibited a significant antibacterial effect when used directly on the S. mutans planktonic cells, but such an effect was not as strong when modifying the PMMA surfaces. These results open the possibility of using polydopamine to reduce the adhesion and growth of S. mutans, which might have important consequences in the dental field.

Integratable micro-optical compound objective lens using soft lithography

Integratable micro-optical compound objective lens using soft lithography

The low temperature liquid metal pressure sensors

Pressure measurement of geotechnical constructions subjected to low temperature plays significant roles in the safety and stability of geotechnical engineering activities. However, the research of pressure sensors in low temperature environment is lacked. In this work, a Galinstan liquid metal pressure sensor under low temperature condition is developed to detect pressure in geotechnical engineering. The elastomer PDMS (polydimethylsiloxane) is employed as the base material. Micro-channels are carved using microfluidic soft lithography technology. The liquid metal is filled as a conductor, and a spring steel case is used for encapsulation. The theoretical relationship between the resistance and pressure is derived, and the theoretical resistance values are compared with experimental resistance values to verify the accuracy of theoretical derivations. The key performance indexes of the designed sensor, such as the compliance, repeatability and hysteresis, are experimentally investigated. The numerical results show that the applied pressure can be uniformly transmitted to the internal PDMS chip with the help of the liquid buffer layer. The experimental results imply that this developed sensor with liquid buffer layer has high curve compliance, good repeatability and low hysteresis in low temperature environment, which provides effective tools for the pressure monitoring of geotechnical constructions subjected to low temperature.

Programming Deformations of 3D Microstructures: Opportunities Enabled by Magnetic Alignment of Liquid Crystalline Elastomers.

Synthetic structures that undergo controlled movement are crucial building blocks for developing new technologies applicable to robotics, healthcare, and sustainable self-regulated materials. Yet, programming motion is nontrivial, and particularly at the microscale it remains a fundamental challenge. At the macroscale, movement can be controlled by conventional electric, pneumatic, or combustion-based machinery. At the nanoscale, chemistry has taken strides in enabling molecularly fueled movement. Yet in between, at the microscale, top-down fabrication becomes cumbersome and expensive, while bottom-up chemical self-assembly and amplified molecular motion does not reach the necessary sophistication. Hence, new approaches that converge top-down and bottom-up methods and enable motional complexity at the microscale are urgently needed. Synthetic anisotropic materials (e.g., liquid crystalline elastomers, LCEs) with encoded molecular anisotropy that are shaped into arbitrary geometries by top-down fabrication promise new opportunities to implement controlled actuation at the microscale. In such materials, motional complexity is directly linked to the built-in molecular anisotropy that can be "activated" by external stimuli. So far, encoding the desired patterns of molecular directionality has relied mostly on either mechanical or surface alignment techniques, which do not allow the decoupling of molecular and geometric features, severely restricting achievable material shapes and thus limiting attainable actuation patterns, unless complex multimaterial constructs are fabricated. Electromagnetic fields have recently emerged as possible alternatives to provide 3D control over local anisotropy, independent of the geometry of a given 3D object. The combination of magnetic alignment and soft lithography, in particular, provides a powerful platform for the rapid, practical, and facile production of microscale soft actuators with field-defined local anisotropy. Recent work has established the feasibility of this approach with low magnetic field strengths (in the lower mT range) and comparably simple setups used for the fabrication of the microactuators, in which magnetic fields can be engineered through arrangement of permanent magnets. This workflow gives access to microstructures with unusual spatial patterning of molecular alignment and has enabled a multitude of nontrivial deformation types that would not be possible to program by any other means at the micron scale. A range of "activating" stimuli can be used to put these structures in motion, and the type of the trigger plays a key role too: directional and dynamic stimuli (such as light) make it possible to activate the patterned anisotropic material locally and transiently, which enables one to achieve and further program motional complexity and communication in microactuators. In this Account, we will discuss recent advances in magnetic alignment of molecular anisotropy and its use in soft lithography and related fabrication approaches to create LCE microactuators. We will examine how design choices-from the molecular to the fabrication and the operational levels-control and define the achievable LCE deformations. We then address the role of stimuli in realizing the motional complexity and how one can engineer feedback within and communication between microactuator arrays fabricated by soft lithography. Overall, we outline emerging strategies that make possible a completely new approach to designing for desired sets of motions of active, microscale objects.

Irreversible PDMS bonding using flame activation of adhesives for fabrication of microfluidic and organ-on-chip devices

Polydimethylsiloxane (PDMS) is widely used for microfluidics fabrication in many disciplines due to its ease of use in soft lithography and its ability to bond liquid-tight seals. A variety of PDMS-PDMS bonding methods exist, but each may have limitations for some applications. For example, chemical bonding via oxygen plasma treatment is reliable but requires expensive equipment and specialized training. Here we present a rapid, low-cost, and accessible method for irreversible PDMS bonding in which flame treatment activates PDMS and Nitto 5302A adhesive surfaces. Using this technique, PDMS microchannels can be fabricated with a bonding integrity of up to 325 kPa burst pressure. This technique is suitable for fabricating organ-on-chip devices that support cell viability and establishment of key cellular features in cell line and primary cell cultures while maintaining bonding integrity.

High‐Performance Blue Perovskite Films and Micro‐Arrays for Light‐Emitting Diodes with Ionic Liquid Interlayer

AbstractMetal halide perovskites have attracted considerable attention for light‐emitting diode (LED) applications due to their desirable optoelectronic properties including high brightness and color purity. However, the performance of blue perovskite LEDs (PeLEDs) remains inferior to their red and green counterparts. Herein, an ionic liquid (IL), specifically 1‐butyl‐3‐methylimidazolium tetrafluoroborate is introduced as the interlayer on the hole transport layer (HTL). This IL demonstrates a strong interaction with the perovskite emissive layer, resulting in effective defect passivation and a shallower valence band maximum. Consequently, nonradiative recombination is reduced, and hole injection is enhanced. Additionally, a soft lithography method employing a transfer process is successfully developed that enables precise micropatterning of the perovskite light‐emitting layer. Through these advancements, the IL‐modified PeLED exhibits pure blue emission at 470 nm with a maximum luminance of 891 cd m−2 and an impressive maximum EQE of 8.3%. Furthermore, the micro PeLED with an IL interlayer achieves a maximum luminance of 400 cd m−2 and a maximum EQE of 3.9%.

Microfluidic delivery of cutting enzymes for fragmentation of surface-adsorbed DNA molecules.

We describe a method for fragmenting, in-situ, surface-adsorbed and immobilized DNAs on polymethylmethacrylate(PMMA)-coated silicon substrates using microfluidic delivery of the cutting enzyme DNase I. Soft lithography is used to produce silicone elastomer (Sylgard 184) gratings which form microfluidic channels for delivery of the enzyme. Bovine serum albumin (BSA) is used to reduce DNase I adsorption to the walls of the microchannels and enable diffusion of the cutting enzyme to a distance of 10mm. Due to the DNAs being immobilized, the fragment order is maintained on the surface. Possible methods of preserving the order for application to sequencing are discussed.

Inexpensive and rapid fabrication of PDMS microfluidic devices for biological testing applications using low cost commercially available 3D printers

Polydimethylsiloxane (PDMS) elastomers have been extensively used in the development of microfluidic devices, capable of miniaturizing biomolecular and cellular assays to the microlitre and nanolitre range, thereby increasing the throughput of experimentation. PDMS has been widely used due to its optical clarity and biocompatibility, among other desirable physical and chemical properties. Despite the widespread use of PDMS in microfluidic devices, the fabrication process typically via soft lithography technology requires specialized facilities, instruments, and materials only available in a limited number of laboratories. To expand microfluidic research capabilities to a greater scientific population, we developed and characterized a simple and robust method of fabricating relatively inexpensive PDMS microfluidic devices using readily available reagents and commercially available three-dimensional (3D) printers. The moulds produced from the 3D printers resolve designed microfluidic channel features accurately with high resolution (>100 µm). The critical physical and chemical post-processing modifications we outline here are required to generate functional and optically clear microfluidic devices.

Bio-Microfabrication of 2D and 3D Biomimetic Gut-on-a-Chip.

Traditional goal of microfabrication was to limitedly construct nano- and micro-geometries on silicon or quartz wafers using various semiconductor manufacturing technologies, such as photolithography, soft lithography, etching, deposition, and so on. However, recent integration with biotechnologies has led to a wide expansion of microfabrication. In particular, many researchers studying pharmacology and pathology are very interested in producing in vitro models that mimic the actual intestine to study the effectiveness of new drug testing and interactions between organs. Various bio-microfabrication techniques have been developed while solving inherent problems when developing in vitro micromodels that mimic the real large intestine. This intensive review introduces various bio-microfabrication techniques that have been used, until recently, to realize two-dimensional and three-dimensional biomimetic experimental models. Regarding the topic of gut chips, two major review subtopics and two-dimensional and three-dimensional gut chips were employed, focusing on the membrane-based manufacturing process for two-dimensional gut chips and the scaffold-based manufacturing process for three-dimensional gut chips, respectively.

Machine learning enhanced droplet microfluidics

Machine learning has recently been introduced in the context of droplet microfluidics to simplify the process of droplet formation, which is usually controlled by a variety of parameters. However, the studies introduced so far have mainly focused on droplet size control using water and mineral oil in microfluidic devices fabricated using soft lithography or rapid prototyping. This approach negated the applicability of machine learning results to other types of fluids more relevant to biomedical applications, while also preventing users that do not have access to microfluidic fabrication facilities to take advantage of previous findings. There are a number of different algorithms that could be used as part of a data driven approach, and no clear comparison has been previously offered among multiple machine learning architectures with respect to the predictions of flow rate values and generation rate. We here employed machine learning to predict the experimental parameters required for droplet generation in three commercialized microfluidic flow-focusing devices using phosphate buffer saline and biocompatible fluorinated oil as dispersed and continuous liquid phases, respectively. We compared three different machine learning architectures and established the one leading to more accurate predictions. We also compared the predictions with a new set of experiments performed at a different day to account for experimental variability. Finally, we provided a proof of concept related to algae encapsulation and designed a simple app that can be used to generate accurate predictions for a given droplet size and generation rate across the three commercial devices.

Anti-reflection effect of high refractive index polyurethane with different light trapping structures on solar cells

The textured surfaces to reduce light reflectivity by using acid-alkali chemical etching and SiNx films are generally necessary for commercial crystalline silicon solar cells. However, this etching process requires a large amount of environmentally harmful acid-alkali solution and has limited options for texture and size. To overcome these disadvantages, a new anti-reflection strategy is proposed in this study, which is using soft nanoimprint lithography to prepare the textured structures on the outside of the SiNx films. The polyurethane with a high refractive index of 1.64 is selected as the texture material, and different templates are selected to prepare it into different light trapping structures, including positive-inverted pyramids, inverted lace cones, and positive-inverted moth-eye nanostructures allowing for easy customization of the textured structures. The finite element simulation and experiments demonstrate that these light trapping structures have a wide spectrum anti-reflection performance in visible and near-infrared bands. With the back surface of the commercial passivated emitter rear contact (PERC) bi-facial solar cells as the imprint substrates, some light trapping structures can reduce the surface weighted average light reflectivity (Rw) at the band of 300–1200 nm from 18.31% to less than 10% and the optimal structures can reduce Rw to 8.71%. This anti-reflection strategy can also be applied to thin-film solar cells and crystalline silicon solar cells of other structures, such as HIT, Topcon, Perovskite/c-Si tandem, and so forth, which shows great development potential.

Method to fabricate round cross-sectional channel using thermal expansion of air for passive flow regulators.

We present a novel method for fabricating round cross-sectional channels for autoregulatory pressure regulators. The application of previously reported methods in multilayered soft lithography using three-dimensional printed molds is challenging. Herein, we used a thermal expansion technique to create round cross-sectional channels in replica layers using air in the cavity space of a master mold. The width and height of the round channel in the replica could be adjusted in the range of 80-300 and 3-57µm, respectively, by varying the precuring time of the replica in the gel state and adjusting the cavity size of the master mold. We successfully fabricated a pressure regulator with a round cross-sectional channel, achieving a constant output pressure at a low threshold input pressure. Our device exhibited superior performance, with a constant output pressure at a threshold input pressure of less than 77%, compared to a device with a rectangular cross-sectional channel. Our method has significant potential for application in the fabrication of integrated microfluidic systems with round cross-sectional channels.

VASCULAR ARTERY SIMULATION MODEL FABRICATION FOR PRE-SURGERY KIT FOR STENT APPLICATION THROUGH 3D PRINTING

Thrombosis occurs of a blood clot in the vein and blocking blood flow. The formation of a clot within the artery is called arterial thrombosis. Due to arterial thrombosis, there are heart attacks and strokes that result in more than 17.9 million deaths worldwide each year. Covid-19, one of today's problems, further increases the mortality rate. The thrombosis mechanism includes factors coming from the blood and the vessel wall. This mechanism is based on local blood flow mechanisms and 3-dimensional (3D) vessel geometry. Microfluidics chip-based vascular models examine the interaction between blood and the vessel wall in vitro studies in thrombosis. Until now, the 3-dimensional geometry of the arteries and blood flow system of healthy or unhealthy individuals have not been fully modeled. In this study, a patient-specific occluded blood vessel model was obtained from computed tomography angiography (CTA) data, and miniature vascular structures were developed with a 3D printer. These structures were printed using Acrylonitrile Butadiene Styrene (ABS). 3D ABS samples were used in Polydimethylsiloxane (PDMS) based soft lithography molds to occur microfluidic systems containing miniaturized replicas of in vivo vessel geometries. A comprehensive simulation of stented vasculature was performed by flow analysis of artificial blood and cell culture by placing a commercial stent on PDMS-based models. This project has aimed to develop and characterize modules by creating microfluidic systems using 3D printers to examine the effects of stents placed in the patient's complex vascular system and to simulate operations before treatment and stent placement.