Replication of a Printed Volatile Mold: a novel microfabrication method for advanced microfluidic systems

AbstractA novel and simple method to fabricate microchannels is reported based on an inkjet printing of a volatile solid mold. A liquid ink -1,6 hexanediol- ejected from a piezoelectric nozzle is instantaneously frozen when touching a cooled substrate. The created mold is then poured with PDMS. Once the PDMS is crosslinked, the ink is sublimated and the device is ready. With this approach it is possible to make microchannels on different nature surfaces such as glass, paper, uncross-linked PDMS layer or non planar substrates. The versatility of this method is illustrated by printing channels directly on commercial electrodes and measuring the channel capacitance. Moreover, millimetric height microfluidic systems are easily produced (aspect ratio $$\ge $$≥ 25) as well as 3D structures such as bridges. To demonstrate, we have fabricated a combinatorial microfluidic system which makes 6 mixtures from 4 initial solutions without any stacking and tedious alignment procedure.

Download Full-text

FABRICATION OF POLYMER MASTER FOR ANTIREFLECTIVE SURFACE USING HOT EMBOSSING AND AAO PROCESS

International Journal of Modern Physics B ◽

10.1142/s0217979208051327 ◽

2008 ◽

Vol 22 (31n32) ◽

pp. 5887-5894 ◽

Cited By ~ 1

Author(s):

HONG GUE SHIN ◽

JONG TAE KWON ◽

YOUNG HO SEO ◽

BYEONG HEE KIM

Keyword(s):

Aspect Ratio ◽

Silicon Layer ◽

Processing Parameters ◽

Hot Embossing ◽

Large Area ◽

Anodized Aluminum ◽

Simple Method ◽

Anodized Aluminum Oxide ◽

Coating Method ◽

Automobile Components

A simple method for the fabrication of polymer master for antireflective surface is presented. In conventional fabrication methods for antireflective surface, coating method with low refractive index have usually been used. However, it is required to have a high cost and a long processing time for mass production. In this paper, antireflective surface was fabricated by using hot embossing process with porous anodized aluminum oxide. Through multi-AAO and etching processes, nano patterned master with high aspect ratio was fabricated at the large area. Size and aspect ratio of nano patterned master are about 175 ± 25 nm and 2 ~ 3, respectively. In order to replicate nano patterned master, hot embossing process was performed by varying the processing parameters such as temperature, pressure and embossing time etc. Finally, antireflective surface can be successfully obtained after etching process to remove selectively silicon layer of AAO master. Optical and rheological characteristics of antireflective surface were analyzed by using SEM, EDX and spectrometer inspection. Antireflective structure by replicating hot embossing process can be applied to various displays and automobile components.

Download Full-text

UV crosslinkable emulsions with silver nanoparticles for inkjet printing of conductive 3D structures

Journal of Materials Chemistry C ◽

10.1039/c3tc30253a ◽

2013 ◽

Vol 1 (19) ◽

pp. 3244 ◽

Cited By ~ 29

Author(s):

Michael Layani ◽

Ido Cooperstein ◽

Shlomo Magdassi

Keyword(s):

Silver Nanoparticles ◽

Inkjet Printing ◽

3D Structures

Download Full-text

Application of microfluidic systems for neural differentiation of cells

Precision Nanomedicine ◽

10.33218/prnano2(4).181127.2 ◽

2019 ◽

Vol 2 (4) ◽

pp. 370-381

Author(s):

Zahra Hesari ◽

Fatemeh Mottaghitalab ◽

Akram Shafiee ◽

Masoud Soleymani ◽

Rasoul Dinarvand ◽

...

Keyword(s):

Stem Cells ◽

Small Molecules ◽

Neuronal Differentiation ◽

Neural Differentiation ◽

Three Dimensional ◽

Microfluidic System ◽

Microfluidic Systems ◽

Cell Culture Systems ◽

Novel Model ◽

Dimensional Cell

Neural differentiation of stem cells is an important issue in development of central nervous system. Different methods such as chemical stimulation with small molecules, scaffolds, and microRNA can be used for inducing the differentiation of neural stem cells. However, microfluidic systems with the potential to induce neuronal differentiation have established their reputation in the field of regenerative medicine. Organization of microfluidic system represents a novel model that mimic the physiologic microenvironment of cells among other two and three dimensional cell culture systems. Microfluidic system has patterned and well-organized structure that can be combined with other differentiation techniques to provide optimal conditions for neuronal differentiation of stem cells. In this review, different methods for effective differentiation of stem cells to neuronal cells are summarized. The efficacy of microfluidic systems in promoting neuronal differentiation is also addressed.

Download Full-text

Development of Planar Microfluidic Systems Using Conventional and Low Temperature Assembling Schemes for Components

10.1115/imece1999-0277 ◽

1999 ◽

Author(s):

Nihat Okulan ◽

Shekhar Bhansali ◽

Arum Han ◽

Saman Dharmatilleke ◽

Jin-Woo Choi ◽

...

Keyword(s):

Low Temperature ◽

Electrochemical Detection ◽

Biochemical Analysis ◽

Magnetic Particle ◽

Lab On A Chip ◽

Microfluidic System ◽

Microfluidic Systems ◽

Detection Techniques

Abstract This center is currently working on the development of a remotely accessible generic microfluidic system (“lab on a chip”) for biological and biochemical analysis, based on electrochemical detection techniques. Modular microfluidic components, including micro reservoirs, microvalves, micropumps, filterless magnetic particle separators, biosensors and flowsensors, were fabricated and tested, and integrated on a system motherboard. Other air-to-liquid measurand concentrators and integrated sieve/filters are being explored in related efforts. The fabrication of these microfluidic components and the utilization of wax for low temperature assembly and even bonding is discussed.

Download Full-text

UV-LED Lithography for Millimeter-Tall High-Aspect Ratio 3d Structures

2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) ◽

10.1109/transducers.2019.8808180 ◽

2019 ◽

Author(s):

Jungkwun Kim

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

3D Structures ◽

Uv Led

Download Full-text

The Fabrication and Application Mechanism of Microfluidic Systems for High Throughput Biomedical Screening: A Review

Micromachines ◽

10.3390/mi11030297 ◽

2020 ◽

Vol 11 (3) ◽

pp. 297 ◽

Cited By ~ 1

Author(s):

Kena Song ◽

Guoqiang Li ◽

Xiangyang Zu ◽

Zhe Du ◽

Liyu Liu ◽

...

Keyword(s):

High Throughput ◽

New Technologies ◽

Biomedical Application ◽

Raw Materials ◽

Physical Structure ◽

Microfluidic System ◽

Microfluidic Chips ◽

Microfluidic Systems ◽

Microfluidic Technology

Microfluidic systems have been widely explored based on microfluidic technology, and it has been widely used for biomedical screening. The key parts are the fabrication of the base scaffold, the construction of the matrix environment in the 3D system, and the application mechanism. In recent years, a variety of new materials have emerged, meanwhile, some new technologies have been developed. In this review, we highlight the properties of high throughput and the biomedical application of the microfluidic chip and focus on the recent progress of the fabrication and application mechanism. The emergence of various biocompatible materials has provided more available raw materials for microfluidic chips. The material is not confined to polydimethylsiloxane (PDMS) and the extracellular microenvironment is not limited by a natural matrix. The mechanism is also developed in diverse ways, including its special physical structure and external field effects, such as dielectrophoresis, magnetophoresis, and acoustophoresis. Furthermore, the cell/organ-based microfluidic system provides a new platform for drug screening due to imitating the anatomic and physiologic properties in vivo. Although microfluidic technology is currently mostly in the laboratory stage, it has great potential for commercial applications in the future.

Download Full-text

Inkjet printing-based fabrication of microscale 3D ice structures

Microsystems & Nanoengineering ◽

10.1038/s41378-020-00199-x ◽

2020 ◽

Vol 6 (1) ◽

Author(s):

Fengyi Zheng ◽

Zhongyan Wang ◽

Jiasheng Huang ◽

Zhihong Li

Keyword(s):

Inkjet Printing ◽

Degrees Of Freedom ◽

Growth Direction ◽

Ice Crystals ◽

Maximum Height ◽

Landing Point ◽

Printing Process ◽

3D Structures ◽

Low Humidity ◽

Supporting Material

Abstract This study proposed a method for fabricating 3D microstructures of ice without a supporting material. The inkjet printing process was performed in a low humidity environment to precisely control the growth direction of the ice crystals. In the printing process, water droplets (volume = hundreds of picoliters) were deposited onto the previously formed ice structure, after which they immediately froze. Different 3D structures (maximum height = 2000 µm) could be formed by controlling the substrate temperature, ejection frequency and droplet size. The growth direction was dependent on the landing point of the droplet on the previously formed ice structure; thus, 3D structures could be created with high degrees of freedom.

Download Full-text

Optical Projection Tomography Using a Commercial Microfluidic System

Micromachines ◽

10.3390/mi11030293 ◽

2020 ◽

Vol 11 (3) ◽

pp. 293

Author(s):

Wenhao Du ◽

Cheng Fei ◽

Junliang Liu ◽

Yongfu Li ◽

Zhaojun Liu ◽

...

Keyword(s):

Three Dimensional ◽

Numerical Aperture ◽

Microfluidic System ◽

Depth Of Field ◽

Objective Lens ◽

Flow Mode ◽

Wide Field ◽

Optical Projection Tomography ◽

Microfluidic Systems ◽

Optical Projection

Optical projection tomography (OPT) is the direct optical equivalent of X-ray computed tomography (CT). To obtain a larger depth of field, traditional OPT usually decreases the numerical aperture (NA) of the objective lens to decrease the resolution of the image. So, there is a trade-off between sample size and resolution. Commercial microfluidic systems can observe a sample in flow mode. In this paper, an OPT instrument is constructed to observe samples. The OPT instrument is combined with commercial microfluidic systems to obtain a three-dimensional and time (3D + T)/four-dimensional (4D) video of the sample. “Focal plane scanning” is also used to increase the images’ depth of field. A series of two-dimensional (2D) images in different focal planes was observed and compared with images simulated using our program. Our work dynamically monitors 3D OPT images. Commercial microfluidic systems simulate blood flow, which has potential application in blood monitoring and intelligent drug delivery platforms. We design an OPT adaptor to perform OPT on a commercial wide-field inverted microscope (Olympusix81). Images in different focal planes are observed and analyzed. Using a commercial microfluidic system, a video is also acquired to record motion pictures of samples at different flow rates. To our knowledge, this is the first time an OPT setup has been combined with a microfluidic system.

Download Full-text

Modeling Living Cells Within Microfluidic Systems Using Cellular Automata Models

Scientific Reports ◽

10.1038/s41598-019-51494-1 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Julia Ballesteros Hernando ◽

Milagros Ramos Gómez ◽

Andrés Díaz Lantada

Keyword(s):

Cellular Automata ◽

Growth Rates ◽

Computational Models ◽

Disease Modeling ◽

Petri Dish ◽

Microfluidic System ◽

Microfluidic Systems ◽

Cell Behaviors ◽

Cad Models ◽

Organ On A Chip

Abstract Several computational models, both continuum and discrete, allow for the simulation of collective cell behaviors in connection with challenges linked to disease modeling and understanding. Normally, discrete cell modelling employs quasi-infinite or boundary-less 2D lattices, hence modeling collective cell behaviors in Petri dish-like environments. The advent of lab- and organ-on-a-chip devices proves that the information obtained from 2D cell cultures, upon Petri dishes, differs importantly from the results obtained in more biomimetic micro-fluidic environments, made of interconnected chambers and channels. However, discrete cell modelling within lab- and organ-on-a-chip devices, to our knowledge, is not yet found in the literature, although it may prove useful for designing and optimizing these types of systems. Consequently, in this study we focus on the establishment of a direct connection between the computer-aided designs (CAD) of microfluidic systems, especially labs- and organs-on-chips (and their multi-chamber and multi-channel structures), and the lattices for discrete cell modeling approaches aimed at the simulation of collective cell interactions, whose boundaries are defined directly from the CAD models. We illustrate the proposal using a quite straightforward cellular automata model, apply it to simulating cells with different growth rates, within a selected set of microsystem designs, and validate it by tuning the growth rates with the support of cell culture experiments and by checking the results with a real microfluidic system.

Download Full-text