Microfluidic prototyping serves as a critical foundation for transitioning lab-on-a-chip systems and droplet microfluidics applications from early-stage research to scalable production. As these systems mature beyond academic research into clinical diagnostics, biopharmaceutical development, and environmental sensing, the requirement for prototyping methods aligned with industrial manufacturing constraints becomes essential. This article outlines current challenges in microfluidic chip fabrication and highlights strategies for bridging the gap between initial concept and manufacturable device using thermoplastic-compatible, production-representative prototyping workflows. When Microfluidic Prototypes Fail to Scale Many microfluidic projects encounter the same problem: a device performs well in the lab but fails during production transfer. Common scale-up issues include: Channel deformation or incomplete replication during molding Bonding yield below acceptable production levels Warpage after thermal cycling Inconsistent feature replication across cavities Optical distortion affecting detection performance Tool redesign adding 4–6 months to timeline Most of these problems originate not in production, but in early-stage design decisions. Scalable microfluidic prototyping must therefore validate not only fluidic function, but also manufacturability. Limitations of Traditional Prototyping in Microfluidics Polydimethylsiloxane (PDMS) has been the material of choice for microfluidic prototyping in academic environments due to its optical clarity, elastomeric properties, and ease of fabrication via soft lithography. However, PDMS introduces significant limitations when transitioning to industrial-scale production: Incompatibility with high-volume manufacturing methods (e.g., injection molding) Poor long-term chemical resistance and mechanical stability Surface chemistry unsuitable for many biological or chemical applications Limited control over reproducibility and batch-to-batch consistency To enable effective product development pipelines, prototyping workflows must incorporate materials and processes that are compatible with downstream manufacturing technologies. Design Considerations for Scalability To ensure seamless transition from prototype to production, critical microfluidic design parameters must be optimized early in development: Minimum feature size: Defines limits of channel width and depth, dependent on manufacturing process and material Aspect ratios: Impact flow behavior and manufacturability (particularly relevant in droplet microfluidics) Internal radii and surface transitions: Affect bonding uniformity and flow consistency Junction geometry: Especially crucial in emulsification and multiphase systems These parameters influence not only fluidic behavior but also the success of micro injection molding and post-processing steps such as bonding and surface treatment. For more on mold design strategies, see injection mold design basics. Focused Prototyping: Validating What Matters In scalable product development, microfluidic prototyping is not a separate step, it’s the foundation of a successful manufacturing strategy. A well-structured prototyping phase allows teams to validate functionality, assess manufacturability, and de-risk production early. Manufacturing-Ready Validation At Micromolds, we start with design optimization, addressing critical parameters that impact both performance and manufacturability, including: Minimum channel depth and width Feature density and aspect ratios Internal radii limits Junction geometries, particularly for droplet microfluidics These factors are essential not only for functional validation but also for ensuring design-for-manufacturing (DFM) compatibility, especially when transitioning to micro injection molding. For a broader manufacturing perspective, see micro milling microfluidic chips. Our Approach to Scalable Microfluidic Prototyping At Micromolds, microfluidic prototyping is treated as the first phase of production — not a temporary experimental step. Our engineering approach includes: Design-for-manufacturing (DFM) review Thermoplastic-first prototyping strategy In-house micro tooling expertise Feature replication validation Production-representative bonding workflows Early assessment of molding feasibility By aligning prototype fabrication with injection molding constraints, we reduce risk and eliminate costly redesign cycles. Material Selection for Scalable Microfluidic Prototyping Unlike PDMS or glass, thermoplastics offer a unique combination of scalability, chemical resistance, and functional adaptability, making them ideal for industrial-scale microfluidic chip fabrication. Common thermoplastic materials: COC (cyclic olefin copolymer): High optical clarity, low water absorption, excellent for optical sensing COP (Cyclic Olefin Polymer): Similar to COC, but with higher chemical resistance and purity, ideal for pharmaceutical and diagnostic applications PMMA (acrylic): Affordable, easy to machine, moderate chemical resistance PC (polycarbonate): Strong, durable, with good optical properties Critical Material Properties: Optical performance: High transparency and low autofluorescence are essential in systems relying on microscopy, fluorescence imaging, or laser interrogation. These characteristics improve signal-to-noise ratios, especially in droplet microfluidics, where detection precision is critical. Thermal and mechanical stability: Thermoplastics maintain dimensional integrity under thermal cycling, pressure, and physical handling, key for bonding reliability and long-term structural performance. Surface chemistry tunability: Surfaces can be tailored for specific fluidic functions, including hydrophilic/hydrophobic patterning, bio-coating compatibility, or protein repellency, enhancing assay fidelity. Bonding scalability: One of the main advantages of thermoplastics is their compatibility with multiple scalable bonding techniques. These materials support thermal, solvent, laser, and ultrasonic bonding, each of which can be selected based on production scale, feature geometry, and cycle time. This flexibility enables smooth transitions from prototype to high-throughput manufacturing without redesigning the core microfluidic layout. Material choice is inseparable from fabrication strategy, affecting everything from optical readout quality to bonding yield and throughput. Thermoplastics not only align with industrial workflows but also enhance functional performance when selected and implemented thoughtfully. For a detailed comparison of thermoplastics with other materials like glass and silicon, see our article: Thermoplastics vs Glass and Silicon in Microfluidics. Preparing Microfluidic Designs for Injection Molding To achieve scalable manufacturing in microfluidics, design decisions must account for the realities of high-volume production from the earliest stages of prototyping. Injection Molding Challenges Micro injection molding is a widely adopted method for producing plastic microfluidic chips at scale, but it comes with specific engineering constraints that must be addressed during design. Key challenges when transitioning to injection molding include: Maintaining replication fidelity of micro-scale features Ensuring process repeatability across production runs Achieving consistent bonding and sealing performance Controlling cost per unit at volume Applying DFM Principles Early By integrating design-for-manufacturing (DFM) principles early — such as appropriate feature sizing, draft angles, and material compatibility — teams can reduce risk, accelerate time to production, and ensure that prototypes are truly scalable. Understanding the capabilities and limits of micro injection molding is essential for a smooth path from functional prototype to mass-produced device. Real-World Applications of Scalable Microfluidic Prototyping Scalable prototyping enables faster innovation in a wide range of industries. Common applications include: Point-of-care diagnostics Single-cell analysis Drug delivery and screening Organ-on-a-chip systems Environmental and chemical testing Early functional validation using scalable methods ensures that designs are technically and economically viable before regulatory or production barriers emerge. Teams can refine critical performance aspects, optimize material choices, and prepare for manufacturing without compromising development timelines. Validate Your Microfluidic Design for Scalable Manufacturing If you are developing a microfluidic device and planning transition to injection molding, early manufacturability validation can significantly reduce risk. Our engineering team supports: DFM assessment for microfluidic chips Thermoplastic prototyping aligned with production Micro injection molding feasibility review Tooling strategy consultation Discuss your microfluidic project with our engineering team and explore a scalable manufacturing pathway. → Talk to a Microfluidics Engineer → Request DFM Feedback

This week we had guests of Directors of the Alliance of Lithuanian Clusters. On the meeting agenda was Lithuanian clusters future and perspectives where CoMI had an opportunity to present its strategy and collaboration opportunities across the country. We had an honour to show our premises for the guests and introduce them to micro molding technology too. Our CEO explained the differences between micro injection molding and traditional injection molding. The guests had a chance to check on how micromolding machines and micro-milling works as well as to touch and feel still hot molded samples.

"OVAO" is a virtual swimming training assistant, a startup company founded by 5 Lithuanians: Aldas, Justinas, Kamile, Marius and Mindaugas. They firmly claim that this swimming couching device is one of the most convenient and practical of all in the market. It can be used by both - amateur or professional swimmers and triathletes. This device has no analogues and solves a very actual problem, which is faced by many swimmers - tracking swimming training biometrics. This virtual assistant works much better than a regular wearable smart watch on the wrist and it is much more comfortable to use while swimming. This is due to the simple technology that allows swimmers to attach this device to almost any swimming goggle's strap. The main advantage of "OVAO" is that it estimates the heart rate by measuring the pulse of the temple artery, which provides very accurate data on the heart condition and regime of the whole workout. Everything is measured in real time and can be viewed in the phone app after the workout. The device gives information to the athlete through the light signals - blinking frequency and changing colours. If "OVAO" changes colour to blue, that means that swimmers heart-zone pursuing 60-70 % of MHR (Maximum Heart Rate). This mode is the best for people, who want to lose weight. When goggles turn orange, that means swimmer is speeding up about 80-90% of MHR and it indicates that a person is training to improve the cardiovascular system. This device will allow you to choose a training program based on your goals. It means, that if you are swimming too slow or too fast for the program you chose, "OVAO" will inform you by flashing LED-indicator which tell you that you need to change speed. In addition, virtual swimming training assistant also tracks all important parameters of swimming results, including lap time, distance swam, lap count, stroke rate, average pace, calories burned, etc. Project uniqueness and complexity gathered numbers of professionals. The team included electrical technicians, mechanical engineers, programmers and investors. It is worth mentioning that this project caught attention of one of the biggest venture capital fund in Lithuania - „Nextury Ventures“ led by famous entrepreneur Ilja Laurs. We are proud that "Micromolds" team, played main role in mechanical engineering area and was responsible for designing the product and its prototyping process. One of the biggest challenges in housing design was insulation and water resistance at high water pressure. Insulation issue was further burdened with more design requirements: housing had to have sections of transparent surfaces for measuring the pulse of the artery and a flexible LED light transmitter rod. We used ABS (acrylonitrile butadiene styrene) thermoplastic material for housing injection moulding and PC (polycarbonate) plastic over-molding for transparent sections in the moulded housing. Also, we used TPE (thermoplastic elastomer) to encapsulate flexible sensor holder arm and fix it to the main body. We sealed the remaining joints with ultrasonic welding. Sophisticated structure of the product had to be optimized for injection moulding manufacturability and over-moulding processes. Afterwards, we launched for prototyping and used SLA (stereolithography) and FDM (fused deposition modeling) 3D printing technologies for it. SLA technology is based on photo-sensitive liquid resin which solidifies when illuminated. SLA enables prototyping of flexible parts and in this case was used for clickable button and bendable sensor extension prototypes. We used FDM 3D printing technology for main housing prototype. It works when fused plastic dispenser head moves vertically and horizontally and layer by layer dispenses plastic creating a 3D shape. We were able to see how new product has been developing from up close. Understanding not only engineering side of project gave us great value in working with teams. We saw how new product is delivered to the market and how important is to maintain "LEAN" mindset when creating MVPs and what challenges startup teams face. We had a lot of communication inside our team which led us to learn that every project detail is more cross-linked than we have imagined. Perceived knowledge has enriched us as a company and encouraged to work harder to reach for more similar projects so we could not only provide with on-demand manufacturing services but also create something new and innovate. We believe that there will be more projects like this in the future and we cannot wait for new challenges.

Droplet microfluidics is a recent trend of laboratory automation technologies, which allow scientists to explore the biological world at an unprecedented resolution and throughput. The new infrastructure is powered by innovative instrumentation, software as well as the consumable reagents and chips. In this context, plastic chips play a key role in enabling these applications, as they ensure a consistent and scalable droplet production. What are the microfluidic chips? At the foundations of droplet microfluidics are the chips used for high-speed droplet generation, injection, splitting, merging, mixing and storing. However, specialist injection moulding knowledge is required for producing chip features with micrometer resolution. Material science expertise is equally important as chosen plastics need to be compatible with fluorinated oils and biological analysis workflows. Finally, mechanical design is also important, as plastic chips feature a combination of microscopic features defining microfluidic functions, in addition to the macroscopic chip features like snap fits for assembly and liquid containers (wells). High volume chips’ molding When microfluidic channels are tested and confirmed for the desired research objective, higher volume of the chips may be demanded and this is where Micromolds company with micro injection moulding steps in. Not only does injection moulding come handy because of its high productivity but also because it enables the possibility to make non-micro structures – like the reservoirs, wells, inlet and outlet gates together with micro geometries in one single moldable piece. However, this comes at a certain cost which is challenging for any injection molding professional. Tooling challenges When things get really small, regular machining might not be an option even though theoretical machine and tool precision would let do so. For such micro tools we had to use tool inserts that are located inside the mold base. Since the high plastic injection pressures forces are exerted inside the mold cavity and core, we had to experiment a lot with different machining options of those inserts – from laser ablation to multiphoton polymerization. Manufacturing the insert is just one side of a coin, the most challenging task was to locate the insert inside the mold base so that alignment of the core and cavity would be perfect and the clamping forces would not brake the inserts. Injection Challenges Extremely flat surface of the chip was needed to make micro geometries possible. This meant that any sink marks caused by the uneven wall thickness had to be solved. However, we could not make walls thinner than the smallest ejectors we had since this would have caused us demolding problems. In fact, it did. At the first trials the ejectors were too weak and started to bend. As a way out we had to play with injection parameters to reduce the sink marks to the minimum so the wall thickness could remain unchanged and thus thicker ejectors could be used. The results We are excited to participate in the development and production of droplet microfluidic tools for the life science sector. We constantly grow with our customers by pushing together on the technical limits of plastic chip designs and enabling new applications, which finally contribute to modern biological research and human health.

In this case our client was a global high-tech company working on a cutting-edge electro-optic systems for applications in defense and security industries. Their products range from unmounted warrior systems, border surveillance and OEM solutions for airborne and naval integrations. Over-molding the Cables Innovation frequently leads to a creation of something customized and non-standard. In this case - custom-made cables. Wire over-moulding process is used to protect cable from strain and bending forces and mechanical wear near the termination points or contacts. Sometimes over-moulding for cables is used not only for cable protection from shocks and folding but also for branding, where companies' logo can be easily casted with plastic injection method. In this case only over-moulded protective covering was required. Aluminium dies were CNC machined. For encapsulation we used TECHNOMELT® PA678 BLACK thermoplastic polyamid which has good adhesive characteristics and thus is very suitable for encapsulation. Thanks to its low viscosity this plastic can be used for low-pressure injections which is good for over-moulded components located inside the cavity. We also used additional insert seen in the upper and below pictures with wires passing through it. The insert was used to position cable and fully enclose cavity for smooth injection and solidification around the cable. The cable was screwed to the insert to maintain constant positioning and fully enclosed cavity. Injection molding might leave minor marks and blemishes - called flashes on a work-piece. These appear due to deviations and errors in mould size and machining inaccuracies, also, due to incorrect pressure settings which should be adjusted during the process. Also, little marks can be seen punched by ejector pins while pushing cast out of the cavity. Usually these drawbacks are unavoidable but can be minimized by using high precision tools and expert level of engineering skills, thankfully, our results prove us to be just like that. Button Prototype Injection Moulding There is no secret that electronics industry is high in demand for buttons and switches. Newly designed devices sometimes require custom-made knobs to turn on/off variety of functions. Buttons stand between human and machine and lets interact him with it, thus, its design becomes crucial for good user experience. We've been contracted to mould prototype button from thermoplastic elastomer (TPE) hardness of 60 Shore A. These kind of materials are a class of co-polymers that has both thermoplastic and elastomeric characteristics. TPE makes button soft, grippy and flexible. However, when making non-standard button, dimensions and form can have huge impact on button's functionality. Button has to bounce back when pushed and create a good user experience by giving a feeling that it has actually been clicked. As we were about to make prototypes we decided to fit 4 button designs in one mould. However, we also expected that we might get it just right at first trial, so we decided to save on tooling costs and designed only one button with space buffer for 3 more buttons including area for runners and vents. We have used CNC milling for aluminium mould and EDM (electrical discharge machining) for surface finish. Our expectations were right. The moulded prototype was perfect at first shots. We and our contractor agreed that we can firmly scale production without any further prototyping. Anyway, saved space in the mould will be easily used for future projects, having in mind our close partnership with our existing clients.

Another project another innovation? We are always glad to apply and share our manufacturing knowledge and experience with innovating companies of any kind. Not only companies, though. At MicromoldsTM we take social responsibility seriously and this project proves us not being just talkers but also doers. Neurosurgeries and manufacturing? Together with the students from Vilnius University (VU) and the neurologists of Vilnius University “Santaros” Clinics we have designed and manufactured a head frame which is used as a locator device for fixing stereotactic arc position. Stereotactic arc is a clinical instrument that allows surgeons to detect and apply the desired trajectory for a stereotactic intervention. Stereotactic (or stereotaxic) interventions, theoretically, are supposed to be performed for treatments of any organ system inside a human body. However, these have only been applied in neurosurgeries (performed on brain) so far yet. What is also worth mentioning is that neurology is quite a new discipline as a field of health sciences. Data about the first use of stereotaxic devices on humans were published in 1933. Since then, the tools of neurosurgical operations were being developed and currently stereotaxic intervention treatments may be applicable for various neurological diseases: from Parkinson’s disease to even cancer (for performing stereotaxic radiosurgeries). Ideas born from problems? The main idea of this project, was to propose a new, reliable and comfortable device to position stereotactic arc more precisely. It was born because of the need of solution for the constantly arising arc positioning problem during the surgical interventions while using stereotactic arcs. In fact, during the surgeries, it is highly possible that any unconscious movements of the patient's head might occur and the consequences of these involuntary actions might be tragic. Before the head frame idea came as a solution, someone had always had to hold the head of the patient steadily and upright while the neurologist was trying to screw the arc to the skull bone. The process was extremely inconvenient and risky. Let us offer a solution Our 3D Printed Head Frame now can be used by surgeons to pre-position the stereotactic arc by attaching it to the frame by using pins and screws. Thus, the preparation and process of a surgical intervention have become more convenient and reliable, since the head, frame and arc can be locked together in one immobile system. No assistance would be needed anymore and the positioning error of a stereotactic arc can be minimized. Head stable while head frame sustainable? For frame prototype manufacturing we used PLA (thermoplastic polyester) - plastic suitable for additive manufacturing FDM (Fused Deposition Modelling). PLA is currently one of the mostly used polyesters in 3D printing. This thermoplastic polyester is considered to be a bioplastic material, since it is sourced from renewable resources rather than from fossil fuels. Also, it may be easily recycled (since PLA has an SPI code 7), incinerated in an economical way (with leaving no residuals and producing a significant amount of energy) or composted till ultimate degradation. And these features of PLA are what makes our 3D printed head frame for stereotactic surgery environmental-friendly. We continuously strive to reduce waste and create sustainable solutions in our projects, while designing and producing economical products from as much renewable and recyclable materials as possible. Not to mention that we are manufacturers on demand. Not to mention that all of our plastic injection molding processes as such are being optimized to save resources and minimize plastic waste. Applying our 3D printing experience The main corpus of the head frame was 3D printed. The following processes were drilling the holes for bushings. Holes were used for placing manually controlled actuators to enable custom positioning configurations for different head sizes and forms. Furthermore, the knobs and fixation pads of the actuators were 3D printed. The assembled final prototype can be seen below in the picture. Job worth doing is worth doing together Our team is happy to collaborate with professionals of the healthcare industry. Not only is exchanging ideas exciting and rewarding, but also turning them into reality and practice is as well. We are highly grateful for an opportunity to contribute to the future of the neurosurgeries and to the future of medicine as a whole. We care about innovation because we believe that this is what drives our future and that is why we have contributed to this project. We are always looking forward to work on scientifically based innovations which would help the experts of their fields to do their job more easily and provide more advanced services and products. Eyes on the prize! There is nothing more exciting to us than to put our efforts on creating something new and helping others. Our team is ambition-driven and we are pushing ourselves towards fulfilling our common mission and achieving our future goals every day.

It’s worthless to repetitively talk about how electrical appliances take up more and more space in our daily lives - electrification is a real boom these days. Electric scooters, robots, electric bicycles, electric cars - the list is endless. It seems only now are we beginning to see the real potential of electric vehicles. However, electrification faces one very important and still not fully solved challenge – energy storage. "EMUS" company is taking this challenge by improving batteries’ management systems and thus extending batteries lifespan. Founded in 2010, "EMUS" company has been working on various control systems for electric vehicles. Over time, "EMUS" has become an exclusive manufacturer of lithium battery management systems. Housing of any electronic gadget supports PCB’s and other electronic components inside, insulates and gives form, design and branding for the final product. This power management system device was not an exception – housing for new product was needed. We are glad that "Micromolds" team was able to provide "EMUS" company with full range of services for this project. We have successfully performed all stages of new product making: Designing and prototyping Optimizing for manufacturing Mould manufacturing Parts production – injection moulding Why did "EMUS" choose us? We halved the tooling costs and time to market in respect of traditional plastic injection moulding. Our mould is 5-6 times smaller than the traditional one, has less cavities, thus it is made much faster and cost of production is significantly smaller. We also use “Babyplast 6/12” injection machine which has low running costs and is made for micro-injection moulding. We do not talk only about numbers. We have CNC milling machines and team of mechanical engineers all under one roof – thus we are able to optimize CAD designs for manufacturability, consult and save by not subcontracting other manufacturers. As expected production volumes were up to 100k pieces per year, our quotation appeared really favourable for EMUS company and we made a contract. What were the main challenges? In order to form PCB fixation hooks with injected plastic, lifters are usually used sliding diagonally in mould plates. This manufacturing technology is relatively complex and thus expensive. In order to keep the costs low our team of engineers used ejectors to form fixators. In this case, the work pieces had to be ejected manually. For a relatively small production volume, this method really paid off. Prototyping For making prototypes we used SLA (stereolithography) - 3D printing technology. Prototypes are manufactured in a layer by layer manner using photochemical processes by which light causes resin to solidify. A total of 3 prototypes were made to look for best functionality and design type. We selected the most suitable product design, performed minor tweaks and jumped straight away into mould making. Material selection and mould manufacturing Choosing the right materials for new product making is no less of importance. Most frequent choice of thermoplastic polymer for electronic housings and enclosures is ABS (Acrylonitrile butadiene styrene). It also works perfectly for plastic injection technology due to its relatively low melting point and good casting properties. ABS material also is favourable because of its low cost. CNC milling machines were used for aluminium mould making. Aluminium moulds work just fine when production volumes do not exceed approximately 100k cycles. EDM technology (electrical discharge machining) was used to create a high-quality surface finish of the outer surface of the product. EDM technology allows to machine work pieces non-mechanically - the product is machined without mechanical force but is exposed to heat treatment, which allows to finish surfaces of complex shaped products. Digital manufacturing is happening now Not only have we become subcontractors for EMUS company and succeeded with this project but also we established lasting relationship by demonstrating advantages of digitalization when two modern companies work together. Sometimes we hear it called online manufacturing – this is what 4th industrial revolution is all about – minimal human intervention. We exchanged our sketches and CAD drawings online, discussed on optimization for manufacturability, also, online and final components were shipped as soon as production was finished. We did not make any physical contact with our client which made everything more automated, faster and safer if taking into account COVID-19.

"Reform" is a Danish modern furniture company designing and manufacturing smart carpentry kitchens. Most of their production is custom-made and sold worldwide in more than 30 countries. The word 'custom' immediately implies that low-volume and fast manufacturing may be the key to a successful work flow. To react fast to the market needs and remain resilient manufacturing partner may be the perfect solution. ''Reform'' and ''Micromolds'' partnership has lessen the risks occurring from changes in the market by supplying on-demand made plastic kitchen cabin spacers. The Design In this case we were able to deliver first batch of spacers in 2 weeks. We used CNC machine for milling aluminium moulds for injection molding. EDM was used for surface finish and logo engraving in the mold. For spacer's manufacturing we used ABS thermoplastic material.