Query: 3D printed microfluidics and microelectronics

Candidate papers:

abstract: Abstract Submillimeter scale domains offer wide ranging benefits for chemical and biological fields, which have motivated researchers to develop a diversity of strategies for manufacturing integrated microfluidic systems. Historically, microfluidic device construction has predominantly relied on micromachining technologies that are rooted in the semiconductor and microelectromechanical systems (MEMS) industries. These methodologies have enabled microfluidic platforms to be fabricated with fully integrated microelectronics a critical requirement for applications such as electrophoresis and dielectrophoresis (DEP) surface acoustic wave (SAW) actuation, digital microfluidics (e.g. via electrowetting on dielectric (EWOD) phenomena) and on chip electrochemical detection. Despite the distinguishing capabilities afforded by conventional microfabrication protocols, a number of inherent limitations have given rise to increasing interest in alternative approaches for microdevice construction in the form of additive manufacturing or "three dimensional (3D) printing" Here we review recent progress in the development of both 3D printed microfluidics and 3D printed microelectronics. We evaluate the distinctive benefits and constraints associated with emerging 3D printing technologies with respect to the fabrication of both microfluidic and microelectronic systems. Lastly, we examine the potential use of 3D printing based approaches for manufacturing microfluidic devices with integrated microelectronics.
author_names: Ryan D Sochol

Eric Sweet

Casey C Glick

Sung-Yueh Wu

Chen Yang

Michael A Restaino

Liwei Lin
title: 3D printed microfluidics and microelectronics
year: 2018

abstract: Microelectromechanical systems (MEMS) are of high interest for recent electronic applications. Their applications range from medicine to measurement technology, from microfluidics to the Internet of Things (IoT) In many cases, MEMS elements serve as sensors or actuators, e.g. in recent mobile phones, but also in future autonomously driving cars. Most MEMS elements are based on silicon, which is not deformed plastically under a load, as opposed to metals. While highly sophisticated solutions were already found for diverse MEMS sensors, actuators, and other elements, MEMS fabrication is less standardized than pure microelectronics, which sometimes blocks new ideas. One of the possibilities to overcome this problem may be the 3D printing approach. While most 3D printing technologies do not offer sufficient resolution for MEMS production, and many of the common 3D printing materials cannot be used for this application, there are still niches in which the 3D printing of MEMS enables producing new structures and thus creating elements for new applications, or the faster and less expensive production of common systems. Here, we give an overview of the most recent developments and applications in 3D printing of MEMS.
author_names: Tomasz Blachowicz

Andrea Ehrmann
title: 3D Printed MEMS Technology Recent Developments and Applications
venue: Micromachines
year: 2020

abstract: Microfluidics devices have high importance in fields such as bioanalysis because these devices have the ability to manipulate small volumes of fluid, typically ranging from microliters to picoliters. Small samples of fluids can be quickly and easily tested using reactions performed with complex microfluidic devices. Many methods have been previously developed to create these devices, including traditional nanolithography techniques borrowed from the field of microelectronics. However, these traditional techniques are cost prohibitive for many small scale laboratories. This research explores a relatively low cost technique using a 3D printed master, which is used as a template for the fabrication of polydimethylsiloxane (PDMS) microfluidic devices. The masters are designed using computer aided design (CAD) software and can be printed and modified relatively quickly. We have developed a protocol for creating simple microfluidic devices using a 3D printer and PDMS adhered to glass. We have also explored methods to overcome the size limits of the 3D printed master templates by using shrinkable polymers and modified channel geometries to create a flow focusing channel. This relatively simple and lower cost technique can now be scaled to more complicated device designs and
author_names: Robyn Collette

Eric C Novak

Daniel Rosen

Kathryn Shirk
title: Developing a Protocol for Creating Microfluidic Devices with a 3D Printer
year: 2015

abstract: In this research an integrated 3D printed laboratory on a chip system was developed based on integrating conventional silicon bio sensing systems with silver screen printed electronics. It was found that by integrating 220mm width micro channels, fabricated using 3D printed polymers, that this offered a means for the development of a microfluidic device with the further possibility for electrically integrating different elements through depositing screen printed silver contacts. The objective was to achieve low resistance and high reliability with low cost for manufacturing 3D printed point of care (POC) diagnostic devices.
author_names: Caitlin McCall

Zari Tehrani
title: 3D printed lab on a chip with microelectronics and silicon integration
year: 2017

abstract: Article history: Received 15 June 2017 Received in revised form 14 December 2017 Accepted 16 December 2017 Available online 21 December 2017 Submillimeter scale domains offer wide ranging benefits for chemical and biological fields, which havemotivated researchers to develop a diversity of strategies formanufacturing integratedmicrofluidic systems. Historically, microfluidic device construction has predominantly relied onmicromachining technologies that are rooted in the semiconductor and microelectromechanical systems (MEMS) industries. These methodologies have enabled microfluidic platforms to be fabricatedwith fully integratedmicroelectronics a critical requirement for applications such as electrophoresis and dielectrophoresis (DEP) surface acoustic wave (SAW) actuation, digital microfluidics (e.g. via electrowetting on dielectric (EWOD) phenomena) and on chip electrochemical detection. Despite the distinguishing capabilities afforded by conventional microfabrication protocols, a number of inherent limitations have given rise to increasing interest in alternative approaches formicrodevice construction in the form of additive manufacturing or "three dimensional (3D) printing" Here we review recent progress in the development of both 3D printedmicrofluidics and 3D printedmicroelectronics. We evaluate the distinctive benefits and constraints associated with emerging 3D printing technologies with respect to the fabrication of both microfluidic and microelectronic systems. Lastly, we examine the potential use of 3D printing based approaches for manufacturing microfluidic devices with integrated microelectronics. (c) 2017 Elsevier B.V. All rights reserved.
author_names: Ryan D Sochol

Eric Sweet

Casey C Glick

Sung-Yueh Wu

Chen Yang

Michael A Restaino

Liwei Lin
title: 3 D printed micro fl uidics and microelectronics
year: 2017

abstract: Abstract Development of a three dimensional (3D) vascular microfluidic chip is one of the important challenges for the study vascular related diseases and new drugs. To date, however, realization of in vivo like blood vessel chips based on soft or photo lithographic fabrication methods have limitations such as complex fabrication processes, tedious manual labor, and frequent assembly failure. In this study, we describe the development of a 3D cell culture chip by utilizing a stereolithographic printer. The microfluidic chip was fabricated using a resin made of 30% (v/v in water) poly(ethylene glycol) diacrylate (MW 700) (30% PEG DA 700) a UV initiator (Irgacure 819 (IRG) and a photosensitizer (2 isopropylthioxanthone (ITX) for constructing a cytocompatible hydrogel structure. The 3D printed cell culture chip is transparent, enabling cell culture and observation of cell proliferation. Endothelial cells were cultured to mimic in vivo like blood vessel architecture within the 3D printed chip. After EAhy926 cell cultivation, cell viability was confirmed by a live/dead cell assay and cultured cells were stained with Calcein AM (Green) and Ethidium homodim 1 (Red) In addition, endothelial cells were successfully cultured in a 3D printed vascular tube like architecture in PEG DA 700. Creating a vascular microfluidic chip with 30% PEG DA 700 hydrogel using automated 3D printing processes reduces fabrication steps and time, avoids any assembly and bonding, and economizes manufacturing cost. We believe our stereolithographic 3D printing method for fabricating a 3D printed vascular chip provides a cost effective, convenient, simple, and reproducible route to vascular related disease modelling and drug screening analyses.
author_names: Yong Tae Kim

Jong Seob Choi

Eunjeong Choi
title: Additive manufacturing of a 3D vascular chip based on cytocompatible hydrogel
year: 2021

abstract: Abstract In this research, an integrated three dimensional (3D) printed laboratory on a chip system was developed based on integrating conventional silicon biosensing systems with silver screen printed electronics. It was discovered that by integrating 220 &mgr;m width microchannels, fabricated using 3D printed polymers, it would offer a means for the development of a microfluidic device with the further possibility for electrically integrating different elements through depositing screen printed silver contacts. The objective was to achieve low resistance and high reliability with low cost for manufacturing 3D printed point of care diagnostic devices.
author_names: Daniel John Thomas

Caitlin McCall

Zari Tehrani

Tim C Claypole
title: Three Dimensional Printed Laboratory on a Chip With Microelectronics and Silicon Integration
year: 1970

abstract: Next generation small satellites, also known as nanosatellites, have masses significantly lower than traditional satellites. Including the propellant mass, the total mass of a nanosatellite is often in the range of 1 to 4 kg. These satellites are being developed for numerous applications related to research, defense, and industry. Since their popularity began in the early 2000's, limitations on the downscaling of propulsion systems has proven to be problematic. Due to this, the vast majority of nanosatellite missions have limited lifespans of 90 120 days in low Earth orbit before they reenter the Earth's atmosphere. Although satellites on this scale have little available space for instrumentation, the development in the fields of microsensors, microelectronics, micromachinery, and microfluidics has increased the capabilities of small satellites tremendously. With limited options for primary propulsion and attitude control, nanosatellites would benefit greatly from the development of an inexpensive and easily implemented propulsion system. This work focuses on the development of an additively manufactured chemical propulsion system suitable for nanosatellite primary propulsion and attitude control. The availability of such a propulsion system would allow for new nanosatellite mission concepts, such as deep space exploration, maneuvering in low gravity environments, and formation flying. Experimental methods were used to develop a dual mode microthruster design which can operate in either low impulse, pseudo monopropellant mode, or high impulse, bipropellant mode. Through the use of a homogeneous catalysis scheme for gas generation, nontoxic propellants are used to produce varying levels of thrust suitable for application in nanosatellite propulsion. The use of relatively benign propellants results in a system which is safe and inexpensive to manufacture, store, transport, and handle. In addition to these advantages, the majority of the propulsion system, including propellant storage, piping, manifolding, reaction chambers, and nozzles can be 3D printed directly into the nanosatellite chassis, further reducing the overall cost of the system. This work highlights the selection process of propellants, catalysts, and nozzle geometry for the propulsion system. Experiments were performed to determine a viable catalyst solution, validate the gas generation scheme, and validate operation of the system.
author_names: Kevin Gagne
title: Development of an Additively Manufactured Microthruster for Nanosatellite Applications
year: 2016

abstract: Computed laminography with synchrotron radiation is developed and carried out for three dimensional (3d) imaging of flat, laterally extended objects with high spatial resolution. Particular experimental conditions of a stationary synchrotron have been taken into account by a scanning geometry different from that employed with conventionally moveable laboratory x ray sources. Depending on the mechanical precision of the employed sample manipulation system, high spatial resolution down to the of scale one micrometre can be attained nondestructively also for objects of large lateral size. Furthermore, the parallel beam geometry enables easy use of monochromatic radiation for optimising contrast and reducing imaging artefacts. The feasibility of the method is demonstrated by the application to the inspection of solder joints in a flip chip bonded device which shows the potential for quality assurance in microsystem devices. Introduction: The development and production of new materials and their application in components in various branches of microelectronics and microsystem technology require information on their structural perfection. Of crucial importance are especially structural properties and their relations to technological steps involved with their production. Moreover, the investigation of structureproperty relationships for the components, starting from semiconductor substrate over layers and lateral structures up to the final component, e.g. the completed laser or integrated circuit, and beyond to the entire device, e.g. the finished PCB unit or hybrid circuit, is needed. Beside laboratory methods, a reliable availability of experimental set ups stations at synchrotron radiation sources with their unique properties (high intensity and brilliance, good coherence properties of radiation at specimen) opens up advanced possibilities for nondestructive material characterization and for nondestructive testing (NDT) of components of applied and industrial research labs. The talk gives an overview illustrating synchrotron radiation inspection and defect analysis in this context by results from microelectronics and microsystem technology, such as ultra thin silicon for smart wafers, macrodefects in GaAs, dislocation density mapping in semiconductor compound wafers, growth and quality of GaN ELO structures on sapphire and SiC, elastic strain in semiconductor nanostructures, metallization layers stress migration in copper conducting lines, lasers mechanical deformation fields in high power laser bars, flipchip technology inspection of solder bumps in sensor arrays and pixel detectors, microfluidics hydrodynamical permeability of micro filters, MOEMS (micro opto electro mechanical structures) stress in micro mirror arrays. Different synchrotron imaging techniques of absorption phaseand diffraction contrast, such as holo tomography, m diffraction, rockingcurve imaging and reciprocal space imaging are employed. In the present paper, results of computed laminography are reported, which has been developed and implemented with synchrotron radiation for the first time and can be considered as a successful extension of three dimensional (3d) synchrotron imaging to flat, laterally extended devices such as microelectronic circuit boards. Today, x ray computed tomography (CT) is one of the principal methods for volume imaging in medical diagnostics and quality assurance. CT has been developed during the 1960s/70s, for cross sectional imaging in medical applications [1,2] and became in the 1980s also widely applied to NDT of materials and devices. With the installation of x ray imaging set ups at synchrotron radiation (SR) sources, highest spatial resolutions down to the submicrometre scale could be reached [3] in radiographic images and weakly contrasted materials be distinguished [4,5,6] by phase contrast imaging. Despite of the great success of CT in general, the CT inspection of flat, laterally extended objects with a high spatial resolution in comparison to the object dimensions (for instance printed circuit boards equipped with integrated circuits) is rather problematic due to strong absorption in the directions parallel to the lateral elongation. Another approach was followed by a method nowadays called classical x ray tomography. Already before the development of CT, it had been used to image specific cross sections of objects (or patients) An acquisition scan consists of synchronous movements of the x ray source and detector with respect to the object and exposing the detector (film) during the scan. In this way the so called focal plane (defined by the geometric trajectories of x ray source, object and detector during the scan) could be investigated: object features on the focal plane are imaged sharply whereas features with growing distance from this plane are rendered increasingly blurred and contribute to a background intensity in the image. The principle was already proposed in 1932 by Ziedses des Plantes [7] for the acquisition of a few arbitrary slices by a single scan. To obtain large 3d images with a multitude of slices, however, a translational scanning of the object with respect to the focal plane has to be carried out. Nowadays, in combination with digital projection data and a computerised reconstruction step [8] the scanning can be avoided: this socalled digital tomosynthesis has analogy to CT with limited angle access. Due to the availability of fast two dimensional (2d) digital detector systems and the tremendous increase of computing power it has recently found renewed interest in medical [8,9] and technical [10,11] applications where the method is also called computed laminography (CL) In this paper the development and implementation of computed laminography with synchrotron radiation, in the following called SRCL, is reported. SRCL combines laminography principles with advantages of SR imaging, owing to the use of monochromatic radiation (due to high brightness of SR) and a high spatial resolution down to the scale of one micron provided by dedicated electronic detector systems. In the following the methodic and instrumental feasibilities are demonstrated by an application to the inspection of flip chip interconnections. The method's potential for nondestructive testing of microsystem technology and devices is outlined by the obtained results. Medical tomosynthesis and laboratory CL systems are usually designed to operate with a stationary patient object and synchronously moving x ray tube and detector units. In contrast to the mobile x ray tube the stationarity of the synchrotron source has to be accounted for by a modified scanning geometry involving now fixed source and detector and a rotation of the object. As sketched in Fig. 1, for SRCL the rotation axis is inclined by an angle of th<p/2 with respect to the monochromatic x ray beam (where the limiting case of th=p/2 would correspond to CT) Figure 1: Sketch of the preliminary experimental set up implemented at beamline ID19 of the ESRF. From a coordinate system fixed to the sample and moving in the laboratory system, this scanning corresponds to synchronous movements of the source and detector on circular trajectories where the x rays follow a conic envelope during the scan. In general for all laminography methods, sampling of the reciprocal sample space is not complete. In comparison to CT there exist unsampled regions which, quite generally, may lead to artefacts in the reconstructed images. Contrary to the laboratory (strongly divergent) cone beam cases reported in [9,12] the approximations of a parallel beam and monochromatic radiation can be very well fulfilled in the case of SR imaging set ups: in the developed implementation at ESRF beamline ID19 (cf. Fig. 1) the high source to sample distance of 145 m leads to a divergence of only approximately 0.02 mrad across the field of view of 2.8 mm of the employed CCD based detector system. For instance, within the precision of one pixel size of 1.4 mm, a maximum sample depth of approximately 7 cm in direction of the x ray beam is allowed in order to stay within parallel beam conditions of one pixel precision. Moreover, the wavelength bandwidth provided by a multilayer monochromator is l/l10 2 compared to l/l1 for the laboratory case. The 3d reconstruction method is based on filtered back projection where the back projection geometry reflects the image acquisition geometry. After determining the modulation transfer function of the projection and back projection processes, a filtering of the 2d projection data is designed to yield an approximate inversion of the back projection process [9,13] In general, due to the missing information in unsampled regions of 3d reciprocal sample space, exact inversion of the back projection process is not possible which manifests in characteristic laminographic artefacts in the reconstructed image. Besides the gain of intensity and resolution of SRCL the monochromatic radiation and parallel beam geometry reduces artefacts compared to laboratory white and cone beam laminography. Results: In order to demonstrate the potential of the method for NDT of microsystem technology we present results of a laminographic scan of a flip chip bonded device. The flip chip device was fixed by means of a cylindrical sample holder made from plexiglass on a rotation table. During the laminographic scan (using axis ph, see Fig. 1) over 360 degrees a total number of 900 projection radiographs was acquired at an x ray energy of 35 keV. An axis inclination of th=p/3 was chosen. Figure 2: Cross sectional slice through the reconstructed 3d data set of a flip chip bonded device (top) A plane parallel to the printed circuit board is shown. 900 projections were acquired with an axis inclination of th=p/3 and at an x ray energy of E= 35 keV. Voxel size is 1.4 mm, image width 1200 voxels. Figure 3: Cross sectional slices perpendicular to the printed circuit board through
author_names: Lukas Helfen

Tilo Baumbach

D Kiel

Petr Mikulik

Petra Pernot

Jose Baruchel

Michael Kroning
title: IMAGING OF MICRO AND NANOSTRUCTURES WITH X RAY TECHNIQUES: APPLICATIONS IN MICROELECTRONICS AND IN MICRO SYSTEM
year: 2004

abstract: The research presented in this thesis explores work on micro and nanoscale patterning and structuring, towards 3D patterning of surfaces. The undertaking of such work is key to the advancement in areas such as microelectronics, nanotechnology and device and sensor fabrication. Chapter 1 (Nanotechnology: Introduction to Small Technology) presents an introduction to the background of the thesis research and information on the concepts and techniques used throughout the thesis. The first experimental chapter, Chapter 2 (Laying the Molecular Foundations) explores the patterning of monomolecular self assembled monolayers (instead of conventional polymeric resists) with electron beam lithography to form chemical patterns on gold surfaces. The chemical patterns on the surface then direct the self assembly of gold nanoparticles with complementary chemistry. Chapter 3 (From the Foundations Upwards) utilises the self assembling ability of the nanoparticles from the previous chapter and explores how they can be incorporated into a multilayer structure on a surface. This multilayer assembly is achieved by the layer by layer deposition methodology in conjunction with a charged polyelectrolyte. The layer by layer deposition process is followed with three different characterization techniques and the results compared. The chapter also examines other routes to directly patterning the layer by layer assembled structures such as photolithography and microfluidics. Chapter 4 (Printing and Scratching) explores the versatility of the nanoparticles and polyelectrolytes (from Chapter 3) towards alternative deposition techniques; in this case, a standard consumer grade inkjet printer is used to deposit the materials to surfaces. Futhermore, an Atomic Force Microscope is then used to define patterns and structures in the printed structures. Chapter 5 (Corrugations and Collagen) introduces the recovery and transfer of micro/nanostructured gold surfaces from gold coated CD R disks to silicon substrates as a route for producing cheap, structured gold substrates. The previous chapters examine methods to control the location of materials on surfaces, the corrugated gold substrates fabricated for this chapter are used to demonstrate that the actual orientation of materials themselves can also be controlled. In this case, the naturally occurring, fibrous and bio technologically interesting material collagen is oriented on a surface by simply rotating the surface in a suspension of collagen in a novel device fabricated for these experiments. The final experimental chapter, Chapter 6 (DNA based Foundations and Walls) uses surface chemical modification to immobilise synthetic hairpin oligonucleotides carrying a photolabile group, on a silicon surface. Once immobilised on a surface, the oligonucleotides are patterned using photolithography to leave exposed single strands, which, through the specific assembly properties of DNA, are used to direct the spatially specific assembly of complementary strands carrying molecular dye or nanoparticle labels. This hybrid system shows that self assembly processes found in nature can be combined with chemical modification of surfaces and oligonucleotide strands to also form 3D dimensional structured surfaces.
author_names: Simon J Leigh
title: The formation and characterisation of micro and nanostructured surfaces through combinations of top down and bottom up fabrication methodologies
year: 2010