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9 pages, 5407 KiB

Open AccessArticle

3D-Printed Soft Structure of Polyurethane and Magnetorheological Fluid: A Proof-of-Concept Investigation of its Stiffness Tunability

by Seong-Woo Hong, Ji-Young Yoon, Seong-Hwan Kim, Sun-Kon Lee, Yong-Rae Kim, Yu-Jin Park, Gi-Woo Kim and Seung-Bok Choi

Micromachines 2019, 10(10), 655; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10100655 - 29 Sep 2019

Cited by 17 | Viewed by 2611

Abstract

In this study, a soft structure with its stiffness tunable by an external field is proposed. The proposed soft beam structure consists of a skin structure with channels filled with a magnetorheological fluid (MRF). Two specimens of the soft structure are fabricated by [...] Read more.

In this study, a soft structure with its stiffness tunable by an external field is proposed. The proposed soft beam structure consists of a skin structure with channels filled with a magnetorheological fluid (MRF). Two specimens of the soft structure are fabricated by three-dimensional printing and fused deposition modeling. In the fabrication, a nozzle is used to obtain channels in the skin of the thermoplastic polyurethane, while another nozzle is used to fill MRF in the channels. The specimens are tested by using a universal tensile machine to evaluate the relationships between the load and deflection under two different conditions, without and with permanent magnets. It is empirically shown that the stiffness of the proposed soft structure can be altered by activating the magnetic field. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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11 pages, 7349 KiB

Open AccessArticle

Miniature 3D-Printed Centrifugal Pump with Non-Contact Electromagnetic Actuation

by Luca Joswig, Michael J. Vellekoop and Frieder Lucklum

Micromachines 2019, 10(10), 631; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10100631 - 21 Sep 2019

Cited by 9 | Viewed by 6173

Abstract

We present a miniature 3D-printed dynamic pump using the centrifugal operating principle. Dynamic pumps typically yield higher flow rates than displacement pumps at reasonable output pressure. Realizing smaller devices suitable for millifluidic and microfluidic applications brings challenges in terms of design, fabrication and [...] Read more.

We present a miniature 3D-printed dynamic pump using the centrifugal operating principle. Dynamic pumps typically yield higher flow rates than displacement pumps at reasonable output pressure. Realizing smaller devices suitable for millifluidic and microfluidic applications brings challenges in terms of design, fabrication and actuation. By using microstereolithography printing we have reduced the overall size to an effective pumping volume of 2.58 mL. The free-moving rotor consists of an impeller and permanent magnets embedded during the printing process, which allow for non-contact electromagnetic actuation. The pump is driven by periodically switching the current through stator coils, controlled by a custom built circuit using a Hall effect sensor. It achieves a maximum flow rate of 124 mL/min and a hydrostatic pressure of up to 2400 Pa. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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7 pages, 2133 KiB

Open AccessArticle

A Nontoxic Battery with 3D-Printed Housing for On-Demand Operation of Microcontrollers in Microfluidic Sensors

by Kai Sachsenheimer, Christiane Richter, Dorothea Helmer, Frederik Kotz and Bastian Ernst Rapp

Micromachines 2019, 10(9), 588; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10090588 - 4 Sep 2019

Cited by 3 | Viewed by 3061

Abstract

Microcontrollers have a low energy consumption and are convenient tools for the operation and readout of small lab-on-a-chip devices. The operation of microcontrollers for data collection and analysis is key for measurements and statistics in field experiments. However, for portable lab-on-a-chip or point-of-care [...] Read more.

Microcontrollers have a low energy consumption and are convenient tools for the operation and readout of small lab-on-a-chip devices. The operation of microcontrollers for data collection and analysis is key for measurements and statistics in field experiments. However, for portable lab-on-a-chip or point-of-care systems in low-resource settings, the availability of energy sources is a bottleneck. Here, we present a simple, nontoxic aluminum/air redox battery with a 3D-printed housing for on-demand operation of a sensor using a microcontroller for data collection. The battery is stored in a dry state and can be manufactured conveniently using off-the-shelf components and a simple 3D printer. It can be quickly assembled and operates a microcontroller for at least one hour in continuous operation mode. We demonstrate its performance by collecting data from a capacitive sensor capable of determining the conductivity of liquid samples. Such sensors can be used for, e.g., determining the water quality or phase formation in liquid mixtures. The sensor performance in determining different conductivities of nonconductive and conductive liquids in droplets is demonstrated. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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Graphical abstract

10 pages, 9313 KiB

Open AccessArticle

3D Printing of Elastic Membranes for Fluidic Pumping and Demonstration of Reciprocation Inserts on the Microfluidic Disc

by Maria Bauer, Adrian Bahani, Tracy Ogata and Marc Madou

Micromachines 2019, 10(8), 549; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10080549 - 19 Aug 2019

Cited by 2 | Viewed by 3403

Abstract

While 3D printing is increasingly used in most fields of engineering, its utilization for microfluidics has thus far been limited. To demonstrate future applications of 3D printing for microfluidic structures, we investigate the fluidic characteristics of material jetted surfaces. We also demonstrate the [...] Read more.

While 3D printing is increasingly used in most fields of engineering, its utilization for microfluidics has thus far been limited. To demonstrate future applications of 3D printing for microfluidic structures, we investigate the fluidic characteristics of material jetted surfaces. We also demonstrate the manufacture of dual-material microfluidic inserts that feature rigid and elastic elements. The fabricated parts are inserted on a microfluidic CD, enhancing design freedom and prototyping capability of over molded parts. Furthermore, printed elastic membranes are tested for fatigue during elastic-pneumatic pumping and rigid and elastic surfaces are characterized with regards to hydrophilicity and surface topography. Finally, different printed disc inserts are demonstrated for moving liquid towards the center of rotation, the mixing of liquids, and controlling burst events through channels width. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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11 pages, 1063 KiB

Open AccessArticle

3D Printed Lab-on-a-Chip Platform for Chemical Stimulation and Parallel Analysis of Ion Channel Function

by Daniel Aschenbrenner, Oliver Friedrich and Daniel F. Gilbert

Micromachines 2019, 10(8), 548; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10080548 - 19 Aug 2019

Cited by 9 | Viewed by 3514

Abstract

Functional imaging has been a widely established method for the assessment of ion channel function in vitro. Conventional infrastructure used for in vitro functional analysis of ion channels is typically proprietary, non-customizable, expensive, and requires a high level of skill to use and [...] Read more.

Functional imaging has been a widely established method for the assessment of ion channel function in vitro. Conventional infrastructure used for in vitro functional analysis of ion channels is typically proprietary, non-customizable, expensive, and requires a high level of skill to use and maintain. 3D desktop printing, which is employed in the rapid prototyping field, allows for quick engineering of alternatives to conventional imaging infrastructure that are customizable, low cost, and user friendly. Here, we describe an ultra-low-cost microfluidic lab-on-a-chip (LOC) device manufactured using acrylonitrile butadiene styrene (ABS) for in vitro functional imaging of ion channels that can quickly and easily be reconstructed using three-dimensional (3D) desktop printing. The device is light weight (<5 g), small (20 mm × 49 mm), and extremely low cost (<EUR 1). We simulate fluidics within the printed channels and assess the suitability of the engineered chamber to generate homogeneous mixtures during solution exchange. We demonstrate the usability of the 3D printed microfluidic device in a case study using Fluo-4-loaded human embryonal kidney-derived (HEK293) cells, recombinantly expressing the capsaicin receptor, transient receptor potential vanilloid receptor type 1 (TRPV1), as a model system. In the case study, we confirm its applicability to solution exchange for chemical stimulation and parallel functional time-lapse fluorescence microscopy-based calcium imaging. We assess the suitability of ABS for culturing HEK293 cells inside the microfluidic LOC, based on qualitative analysis of microscopic transmission light images of ABS-exposed HEK293 cells and confirm the previously reported biocompatibility of ABS. To highlight the versatility of the 3D printed microfluidic device, we provide an example for multiplication of the shown concept within a 3D printed multichannel microfluidic LOC to be used, for example, in a higher throughput format for parallelized functional analysis of ion channels. While this work focusses on Ca²⁺ imaging with TRPV1 channels, the device may also be useful for application with other ion channel types and in vitro models. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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10 pages, 3938 KiB

Open AccessArticle

On the Impact of the Fabrication Method on the Performance of 3D Printed Mixers

by Mojtaba Zeraatkar, Daniel Filippini and Gianluca Percoco

Micromachines 2019, 10(5), 298; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10050298 - 30 Apr 2019

Cited by 20 | Viewed by 2839

Abstract

A wide variety of 3D printing technologies have been used for the fabrication of lab-on-a-chip (LOC) devices in recent years. Despite the large number of studies having examined the use of 3D printing technologies in microfluidic devices, the effect of the fabrication method [...] Read more.

A wide variety of 3D printing technologies have been used for the fabrication of lab-on-a-chip (LOC) devices in recent years. Despite the large number of studies having examined the use of 3D printing technologies in microfluidic devices, the effect of the fabrication method on their performance has received little attention. In this paper, a comparison is shown between unibody-LOC micro-mixers, a particular type of monolithic design for 3D printed LOCs, fabricated in polyjet, stereolithography (SLA) and fused deposition modelling (FDM or FFF) platforms, paying particular attention to the inherent limitations of each fabrication platform and how these affect the performance of the manufactured devices. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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Review

Jump to: Research

39 pages, 2393 KiB

Open AccessReview

3D-Printed Lab-on-a-Chip Diagnostic Systems-Developing a Safe-by-Design Manufacturing Approach

by Panagiotis Karayannis, Fotini Petrakli, Anastasia Gkika and Elias P. Koumoulos

Micromachines 2019, 10(12), 825; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10120825 - 28 Nov 2019

Cited by 14 | Viewed by 5526

Abstract

The aim of this study is to provide a detailed strategy for Safe-by-Design (SbD) 3D-printed lab-on-a-chip (LOC) device manufacturing, using Fused Filament Fabrication (FFF) technology. First, the applicability of FFF in lab-on-a-chip device development is briefly discussed. Subsequently, a methodology to categorize, identify [...] Read more.

The aim of this study is to provide a detailed strategy for Safe-by-Design (SbD) 3D-printed lab-on-a-chip (LOC) device manufacturing, using Fused Filament Fabrication (FFF) technology. First, the applicability of FFF in lab-on-a-chip device development is briefly discussed. Subsequently, a methodology to categorize, identify and implement SbD measures for FFF is suggested. Furthermore, the most crucial health risks involved in FFF processes are examined, placing the focus on the examination of ultrafine particle (UFP) and Volatile Organic Compound (VOC) emission hazards. Thus, a SbD scheme for lab-on-a-chip manufacturing is provided, while also taking into account process optimization for obtaining satisfactory printed LOC quality. This work can serve as a guideline for the effective application of FFF technology for lab-on-a-chip manufacturing through the safest applicable way, towards a continuous effort to support sustainable development of lab-on-a-chip devices through cost-effective means. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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24 pages, 1626 KiB

Open AccessFeature PaperReview

Three-Dimensional Printed Devices in Droplet Microfluidics

by Jia Ming Zhang, Qinglei Ji and Huiling Duan

Micromachines 2019, 10(11), 754; https://0-doi-org.brum.beds.ac.uk/10.3390/mi10110754 - 4 Nov 2019

Cited by 38 | Viewed by 7287

Abstract

Droplet microfluidics has become the most promising subcategory of microfluidics since it contributes numerous applications to diverse fields. However, fabrication of microfluidic devices for droplet formation, manipulation and applications is usually complicated and expensive. Three-dimensional printing (3DP) provides an exciting alternative to conventional [...] Read more.

Droplet microfluidics has become the most promising subcategory of microfluidics since it contributes numerous applications to diverse fields. However, fabrication of microfluidic devices for droplet formation, manipulation and applications is usually complicated and expensive. Three-dimensional printing (3DP) provides an exciting alternative to conventional techniques by simplifying the process and reducing the cost of fabrication. Complex and novel structures can be achieved via 3DP in a simple and rapid manner, enabling droplet microfluidics accessible to more extensive users. In this article, we review and discuss current development, opportunities and challenges of applications of 3DP to droplet microfluidics. Full article

(This article belongs to the Special Issue 3D Printed Microfluidic Devices and Its Applications)

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