Highly-customizable 3D-printed peristaltic pump kit

EnduroBone: A 3D printed bioreactor for extended bone tissue culture

Studies of the effects of external stimuli on bone tissue, disease transmission mechanisms, and potential medication discoveries benefit from long-term tissue viability ex vivo. By simulating the in-vivo environment, bioreactors are essential for studying bone cellular activity throughout biological processes. We present the development of an automated 3D-printed bioreactor EnduroBone designed to sustain the ex-vivo viability of 10 mm diameter cancellous bone cores for an extended period. The device is supplied with two critical parameters for maintaining bone tissue viability: closed-loop continuous flow perfusion of 1 mL/min for nutrient diffusion and waste removal and direct mechanical stimulation with cyclic compression at 13.2 RPM (revolutions per minute) to promote cell viability which can lead to improved tissue stability during ex vivo culturing. The bioreactor addresses several limitations of existing systems and provides a versatile open-source platform for bone cancer research, orthopedic device testing, and other related applications. To validate the bioreactor, fresh swine samples were cultured ex-vivo, and their cell viability was determined to be maintained for up to 28 days. Periodic cell viability assessment through live/dead cell staining and confocal imaging at the start (0 days) and at several time points throughout the culture period (7, 14, 21, and 28 days) was used to demonstrate EnduroBone effectiveness in sustaining bone cell health for the extended period tested.

A User-Centric 3D-Printed Modular Peristaltic Pump for Microfluidic Perfusion Applications

Microfluidic organ-on-a-chip (OoC) technology has enabled studies on dynamic physiological conditions as well as being deployed in drug testing applications. A microfluidic pump is an essential component to perform perfusion cell culture in OoC devices. However, it is challenging to have a single pump that can fulfil both the customization function needed to mimic a myriad of physiological flow rates and profiles found in vivo and multiplexing requirements (i.e., low cost, small footprint) for drug testing operations. The advent of 3D printing technology and open-source programmable electronic controllers presents an opportunity to democratize the fabrication of mini-peristaltic pumps suitable for microfluidic applications at a fraction of the cost of commercial microfluidic pumps. However, existing 3D-printed peristaltic pumps have mainly focused on demonstrating the feasibility of using 3D printing to fabricate the structural components of the pump and neglected user experience and customization capability. Here, we present a user-centric programmable 3D-printed mini-peristaltic pump with a compact design and low manufacturing cost (~USD 175) suitable for perfusion OoC culture applications. The pump consists of a user-friendly, wired electronic module that controls the operation of a peristaltic pump module. The peristaltic pump module comprises an air-sealed stepper motor connected to a 3D-printed peristaltic assembly, which can withstand the high-humidity environment of a cell culture incubator. We demonstrated that this pump allows users to either program the electronic module or use different-sized tubing to deliver a wide range of flow rates and flow profiles. The pump also has multiplexing capability as it can accommodate multiple tubing. The performance and user-friendliness of this low-cost, compact pump can be easily deployed for various OoC applications.

3D-Printed Centrifugal Pump Driven by Magnetic Force in Applications for Microfluidics in Biological Analysis

In recent years, microfluidic systems have been extensively utilized for biological analysis. The integration of pumps in microfluidic systems requires precise control of liquids and effort-intensive set-ups for multiplexed experiments. In this study, a 3D-printed centrifugal pump driven by magnetic force is presented for microfluidics and biological analysis. The permanent magnets implemented in the centrifugal pump synchronized the rotation of the driving and operating parts. Precise control of the flow rate and a wide range and variety of flow profiles are achieved by controlling the rotational speed of the motor in the driving part. The compact size and contactless driving part allow simple set-ups within commercially available culture dishes and tubes. It is demonstrated that the fabricated 3D-printed centrifugal pump can induce laminar flow in a microfluidic device, perfusion culture of in vitro tissues, and alignment of cells under shear stress. This device has a high potential for applications in microfluidic devices and perfusion culture of cells.

Sidekick: A Low-Cost Open-Source 3D-printed liquid dispensing robot

The Sidekick is a desktop liquid dispenser, compatible with standard SBS microplates and designed for accessible laboratory automation. It features an armature-based motion system and a fully 3D-printed chassis to reduce overall mechanical complexity and accommodate user modification. Liquid dispensing is achieved with four commercially available solenoid driven positive displacement pumps that deliver liquid in 10 µL increments. A Raspberry Pi Pico RP2040 processor programmed in MicroPython is used for control, and exposes a USB serial interface for users to submit commands using either a simple vocabulary of commands or a subset of G-Code. At a total cost of $710 USD, the Sidekick offers laboratories an easy to build, easily maintained, open-source liquid dispensing system for both research and pedagogical introductions to lab automation.

Biomimetic Vasculatures by 3D-Printed Porous Molds

Despite recent advances in biofabrication, recapitulating complex architectures of cell-laden vascular constructs remains challenging. To date, biofabricated vascular models have not yet realized four fundamental attributes of native vasculatures simultaneously: freestanding, branching, multilayered, and perfusable. In this work, a microfluidics-enabled molding technique combined with coaxial bioprinting to fabricate anatomically relevant, cell-laden vascular models consisting of hydrogels is developed. By using 3D porous molds of poly(ethylene glycol) diacrylate as casting templates that gradually release calcium ions as a crosslinking agent, freestanding, and perfusable vascular constructs of complex geometries are fabricated. The bioinks can be tailored to improve the compatibility with specific vascular cells and to tune the mechanical modulus mimicking native blood vessels. Crucially, the integration of relevant vascular cells (such as smooth muscle cells and endothelial cells) in a multilayer and biomimetic configuration is highlighted. It is also demonstrated that the fabricated freestanding vessels are amenable for testing percutaneous coronary interventions (i.e., drug-eluting balloons and stents) under physiological mechanical states such as stretching and bending. Overall, a versatile fabrication technique with multifaceted possibilities of generating biomimetic vascular models that can benefit future research in mechanistic understanding of cardiovascular diseases and the development of therapeutic interventions is introduced.

Low cost 3D printing of metals using filled polymer pellets

Nowadays, additive manufacturing of metallic materials is most often carried out using expensive and complex tools that leave the user with limited control and no possibility of modification. In order to make the printing of metal parts more accessible to small structures but also better suited for academic research, the use of a mixture of thermoplastic polymer and metal powder is a good solution as many granular feedstocks already exist for Metal Injection Molding applications. To perform the shaping process, the Fused Granular Fabrication 3D printing technology is set up by diverting the use of a feedstock in the form of pellets that are directly inserted into the print head. This solution, which is less costly, is implemented here by modifying a mid-range printer, the Tool Changer from E3D, and by making the hardware and software adaptations to mount a compact granulates extruder on it, which is also available on the market. The polymer portion present in the green part can then be removed in order to perform the heat treatments that will densify the powder by sintering and give a fully metallic dense object.

The Field Guide to 3D Printing in Optical Microscopy for Life Sciences

The maker movement has reached the optics labs, empowering researchers to create and modify microscope designs and imaging accessories. 3D printing has a disruptive impact on the field, improving accessibility to fabrication technologies in additive manufacturing. This approach is particularly useful for rapid, low-cost prototyping, allowing unprecedented levels of productivity and accessibility. From inexpensive microscopes for education such as the FlyPi to the highly complex robotic microscope OpenFlexure, 3D printing is paving the way for the democratization of technology, promoting collaborative environments between researchers, as 3D designs are easily shared. This holds the unique possibility of extending the open-access concept from knowledge to technology, allowing researchers everywhere to use and extend model structures. Here, it is presented a review of additive manufacturing applications in optical microscopy for life sciences, guiding the user through this new and exciting technology and providing a starting point to anyone willing to employ this versatile and powerful new tool.

Investigating the mechanotransduction of transient shear stress mediated by Piezo1 ion channel using a 3D printed dynamic gravity pump

Microfluidic systems are widely used for studying the mechanotransduction of flow-induced shear stress in mechanosensitive cells. However, these studies are generally performed under constant flow rates, mainly, due to the deficiency of existing pumps for generating transient flows. To address this limitation, we have developed a unique dynamic gravity pump to generate transient flows in microfluidics. The pump utilises a motorised 3D-printed cam-lever mechanism to change the inlet pressure of the system in repeated cycles. 3D printing technology facilitates the rapid and low-cost prototyping of the pump. Customised transient flow patterns can be generated by modulating the profile, size, and rotational speed of the cam, location of the hinge along the lever, and the height of the syringe. Using this unique dynamic gravity pump, we investigated the mechanotransduction of shear stress in HEK293 cells stably expressing Piezo1 mechanosensitive ion channel under transient flows. The controllable, simple, low-cost, compact, and modular design of the pump makes it suitable for studying the mechanobiology of shear sensitive cells under transient flows.

A frugal microfluidic pump

Manipulation of fluid flow is paramount for microfluidic device operation. Conventional microfluidic pumps are often expensive, bulky, complicated, and not amenable in limited resource settings. Here, we introduce a Fully self-sufficient, RobUst, Gravity-Assisted, Low-cost (FRUGAL) microfluidic pump. The pump consists of a syringe, a syringe holder and loading masses. The system is easy to assemble, inexpensive, portable, and electrical power-free. Inside the syringe, the fluid is driven by the pressure from the weight of the loading masses. During operation, the exerted pressure is dynamically controllable and stable for hours. These features are useful for optimization of microfluidics assays and dynamic temporal studies. We demonstrate the application of this system to control the formation of water-in-oil droplet emulsion. Benefitting from its simplicity and versatility, the frugal microfluidic pump will enable global adoption of microfluidic technology in chemistry and biomedical applications, especially in limited resource environments.