Fabrication and Performance Characterization of a Disposable Micropump Actuated by Piezoelectric-Disc

2011 ◽  
Vol 254 ◽  
pp. 179-182 ◽  
Author(s):  
Ling Ling Sun ◽  
Shan Zhong Wang ◽  
Ling Na Li ◽  
Jin Lan Guo ◽  
Siti Fatimatuzzahra Binti Roseli
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Glass Substrate ◽  
Performance Testing ◽  
Microfluidic System ◽  
Driving Voltage ◽  
Pump Rate ◽  
And Performance ◽  
Piezoelectric Disc

Micropumps represent one of the major components in microfluidic technology. This paper describes the fabrication and performance testing of a simple, compact, inexpensive and disposable micropump suitable for microfluidic applications. The micropump was fabricated with polydimethylsiloxane (PDMS) which was bonded permanently on glass substrate. Piezoelectric-discs were used to actuate the micropumps. As a flow-rectifying element, the diffusers were used instead of passive check valves. The performances of the micropump, such as pump rate, were characterized. The flow rate of micropump increases with enhancing the applied voltage to piezoelectric-disc due to the increase of diaphragm deflection. The flow rate of the micropump with diffusers were about 9 μl/min when applying a 20 V square wave driving voltage at 300 Hz. This prototype can be used as a platform to develop an inexpensive micropump which is suitable to be part of a disposable microfluidic system.

Swelling characterization of photo-cross-linked gelatin methacrylate spherical microgels for bioencapsulation

e-Polymers ◽  
2014 ◽  
Vol 14 (3) ◽  
pp. 161-168 ◽  
Author(s):  
Jinmu Jung ◽  
Jonghyun Oh
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Axial Flow ◽  
Microfluidic System ◽  
Low Flow ◽  
Flow Rate Ratio ◽  
Swelling Characteristics ◽  
Irradiation Apparatus ◽  
Proportional Relationship

AbstractThe swelling behavior of biocompatible and biodegradable polymers is important for the delivery and release of cells and drugs in biomedical applications. This study reported the swelling characteristics of photo-cross-linked gelatin methacrylate (GelMa) spherical microgels. Spherical microgels were generated in a microfluidic system consisting of a co-axial flow-focusing device for microdroplet generation and an ultraviolet (UV) irradiation apparatus for polymerization. At a low flow rate ratio (<0.14), the 9 wt.% GelMa spherical microgels were smaller than the 6 wt.% ones. In contrast, at a high flow rate ratio (>0.14), the results were reversed. Overall, a proportional relationship was observed between the flow rate ratio and the droplet size. The increased GelMa concentration improved the mechanical properties and increased the swelling ratios. The possibility of bioencapsulation was demonstrated, with good viability of 3T3 cells encapsulated in the spherical microgels.

Comparing Piezoelectric and Electroosmotic Micropumps for Biomedical Devices

2008 ◽  
Author(s):  
Omer San ◽  
Sinan Eren Yalcin ◽  
Oktay Baysal
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Biomedical Applications ◽  
Low Voltage ◽  
Check Valve ◽  
Back Pressure ◽  
Driving Voltage ◽  
Major Drawback ◽  
Dominant Type ◽  
Flow Rates

A micropump is an essential component of a microfluidic lab-on-a-chip device, especially for their biomedical applications. Based on their actuation method to drive the fluid flow, pumps may be categorized as mechanical or non-mechanical devices. In our proposed paper, we will report our comparative study of the most promising micropumps in each of these categories: a piezoelectrically-actuated micropump (PAμP) and an electroosmotic micropump (EOμP). A PAμP requires relatively high applied voltage, but provides high flow rates and has emerged to be the dominant type of micropump in biomedical applications. A valveless diffuser-nozzle micropump, driven by an oscillating membrane, has an important advantage, since the fabrication of any additional moving part, such as a check valve, would add significantly to its cost and render a more failure-prone device. The piezoelectrically actuated, valveless micropumps use moving mechanical parts to pump fluid and control the flow with optimized actuation frequency and applied voltage. In the present study, the microflow-structure interaction in the PAμP is modeled using an arbitrary Lagrangian-Eulerian method including a parametric study of applied voltage and frequency. An EOμP consists of multiple micron-scale channels in parallel that are subjected to the electroosmotic effect. However, a major drawback in the conventional design of an EOμP is the need for a high driving voltage to increase the flow rate or to overcome the back pressure. In the present study, a low-voltage EOμP is proposed and computationally modeled. Our simulations are performed in order to study the low-voltage EOμP for its various flow rate and back pressure characteristics. In the proposed paper, we will discuss our comparisons of PAμP and EOμP, with respect to their actuation mechanisms, applied voltages, pump sizes, flow rates and back pressures.

Fabrication and Characterization of Electrospun Nano to Microfiber Made of Poly(L-Lactide-co-ε-Caprolactone)

2012 ◽  
Vol 185 ◽  
pp. 122-125
Author(s):  
Genevieve Lin ◽  
Sin Nee Song ◽  
Yee Shan Wong ◽  
Lay Poh Tan ◽  
Kim Yeow Yong ◽  
...  
Keyword(s):  
Process Parameters ◽  
Flow Rate ◽  
Soft Tissues ◽  
Structural Integrity ◽  
Fiber Diameter ◽  
Polymer Concentration ◽  
Driving Voltage ◽  
Electrospun Scaffolds ◽  
Uniform Diameter

This project aims to optimize the process parameters for fabricating Poly (L-Lactide-co-ε-Caprolactone) (PLCL) electrospun scaffolds to achieve fiber diameters within the ranges of ~500nm, 500nm~1µm and 1~3µm. Electronspun PLCL solutions of different concentrations (4wt% - 12wt%) were prepared using chloroform and dimethylformamide as solvents. The driving voltage and flow rate were varied from 10kV-30kV and 1ml/hr12ml/hr respectively while the gap distance was kept constant at 15cm. The effects of polymer concentration and process parameters on the properties of the scaffolds fabricated such as Youngs modulus, degree of crystallization and porosity were studied. Scanning electron microscopy (SEM) was used to check the structural integrity (absence of beading and uniform diameter) of the fibers. An increase in polymer concentration resulted in an increase in fiber diameter. Flow rate also showed a positive correlation with fiber diameter. Results showed that Youngs modulus decreased with increasing fiber diameter. Porosity of 76% to 94% was achieved. The potential application of PLCL electrospun scaffolds in the tissue engineering of soft tissues was discussed.

Novel epoxy/anhydride alternatives for biological electron microscopy: Physical and performance characteristis of embed 812 and LX 112 in combination with NSA/NMA/DMAE

1989 ◽  
Vol 47 ◽  
pp. 1000-1001
Author(s):  
Joe A. Mascorro ◽  
Gerald S. Kirby
Keyword(s):  
Electron Microscopy ◽  
Flow Rate ◽  
Succinic Anhydride ◽  
Volume Flow Rate ◽  
Mass Density ◽  
Uranyl Acetate ◽  
Volume Flow ◽  
Base Resin ◽  
And Performance ◽  
Acid Anhydrides

Embedding media based upon an epoxy resin of choice and the acid anhydrides dodecenyl succinic anhydride (DDSA), nadic methyl anhydride (NMA), and catalyzed by the tertiary amine 2,4,6-Tri(dimethylaminomethyl) phenol (DMP-30) are widely used in biological electron microscopy. These media possess a viscosity character that can impair tissue infiltration, particularly if original Epon 812 is utilized as the base resin. Other resins that are considerably less viscous than Epon 812 now are available as replacements. Likewise, nonenyl succinic anhydride (NSA) and dimethylaminoethanol (DMAE) are more fluid than their counterparts DDSA and DMP- 30 commonly used in earlier formulations. This work utilizes novel epoxy and anhydride combinations in order to produce embedding media with desirable flow rate and viscosity parameters that, in turn, would allow the medium to optimally infiltrate tissues. Specifically, embeding media based on EmBed 812 or LX 112 with NSA (in place of DDSA) and DMAE (replacing DMP-30), with NMA remaining constant, are formulated and offered as alternatives for routine biological work.Individual epoxy resins (Table I) or complete embedding media (Tables II-III) were tested for flow rate and viscosity. The novel media were further examined for their ability to infilftrate tissues, polymerize, sectioning and staining character, as well as strength and stability to the electron beam and column vacuum. For physical comparisons, a volume (9 ml) of either resin or media was aspirated into a capillary viscocimeter oriented vertically. The material was then allowed to flow out freely under the influence of gravity and the flow time necessary for the volume to exit was recored (Col B,C; Tables). In addition, the volume flow rate (ml flowing/second; Col D, Tables) was measured. Viscosity (n) could then be determined by using the Hagen-Poiseville relation for laminar flow, n = c.p/Q, where c = a geometric constant from an instrument calibration with water, p = mass density, and Q = volume flow rate. Mass weight and density of the materials were determined as well (Col F,G; Tables). Infiltration schedules utilized were short (1/2 hr 1:1, 3 hrs full resin), intermediate (1/2 hr 1:1, 6 hrs full resin) , or long (1/2 hr 1:1, 6 hrs full resin) in total time. Polymerization schedules ranging from 15 hrs (overnight) through 24, 36, or 48 hrs were tested. Sections demonstrating gold interference colors were collected on unsupported 200- 300 mesh grids and stained sequentially with uranyl acetate and lead citrate.

Digitalization system of ancient architecture decoration art based on neural network and image features

2020 ◽  
pp. 1-12
Author(s):  
Wu Xin ◽  
Qiu Daping
Keyword(s):  
Neural Network ◽  
Construction Industry ◽  
Three Dimensional ◽  
Performance Testing ◽  
Image Features ◽  
Three Dimensional Model ◽  
Performance Effect ◽  
Data Process ◽  
And Performance ◽  
Construction Mode

The inheritance and innovation of ancient architecture decoration art is an important way for the development of the construction industry. The data process of traditional ancient architecture decoration art is relatively backward, which leads to the obvious distortion of the digitalization of ancient architecture decoration art. In order to improve the digital effect of ancient architecture decoration art, based on neural network, this paper combines the image features to construct a neural network-based ancient architecture decoration art data system model, and graphically expresses the static construction mode and dynamic construction process of the architecture group. Based on this, three-dimensional model reconstruction and scene simulation experiments of architecture groups are realized. In order to verify the performance effect of the system proposed in this paper, it is verified through simulation and performance testing, and data visualization is performed through statistical methods. The result of the study shows that the digitalization effect of the ancient architecture decoration art proposed in this paper is good.

Sign in / Sign up

Export Citation Format

Share Document