Effects of Process Parameters on Direct Deposition Hydrogel Molding for the Fabrication Microfluidic Devices

2016 ◽  
Author(s):  
Karen Chang Yan ◽  
John Sperduto ◽  
Christopher Civitello ◽  
Alison McCarthy ◽  
Aren Moy
Keyword(s):  
Process Parameters ◽  
Electrospun Fiber ◽  
Base Material ◽  
Microfluidic Devices ◽  
Direct Writing ◽  
Channel Diameter ◽  
Curing Conditions ◽  
Direct Deposition ◽  
Method Effects ◽  
And Control

Advantages of microfluidic devices include miniaturization, easy of integration, small reagent consumption etc., and have led to the wide applications in biomedical field. Fabrication of microfluidic devices is commonly done through microfabrication methods; microfabication-free/using rapid prototyping methods have also been developed in recent years to enable applications of microfluidic devices to a broader range. Our recent study has demonstrated the feasibility of fabricating electrospun fiber embedded microfluidic devices by integrating hydrogel molding and electrospinning (ES) through a multi-layer construction process. This paper focuses on examining how process parameters affect microchannel formation in microfluidic devices fabricated using direct-deposition hydrogel molding (dHGM). PDMS (polydimethylsiloxane) was chosen as the base-material of the device, and Agarose hydrogel was used to generate the mold channels. A direct writing system was used to deposit the hydrogel mold. We examined three parameters affecting the dHGM based microchannel formation: hydrogel composition, curing conditions, and deposition method. Effects of these parameters were characterized in terms of ease-of-handling, consistent channel formation, and control of channel diameter.

Deposition Control of a FDM 3D Printer Based Direct Writing System for Hydrogel Molding in Microfluidic Devices Fabrication

2018 ◽  
Author(s):  
Jacob Boyle ◽  
Kristi Petersen ◽  
Karen Chang Yan
Keyword(s):  
Electrospun Fiber ◽  
Microfluidic Devices ◽  
Initial Study ◽  
3D Printer ◽  
Material System ◽  
Direct Writing ◽  
Integrated Method ◽  
Volume Rate ◽  
Wax Printing

Microfabrication-free methods such as wax printing and hydrogel molding have been developed in recent years for fabricating microfluidic devices to enable the applications of microfluidic devices to a broader range. A process has been developed to fabricate electrospun fiber embedded microfluidic devices by integrating hydrogel molding (HGM) and electrospinning (ES), and the feasibility of this integrated method has been demonstrated through our initial study. In particular, agarose gels with various concentrations have been used to generate the channel molds inside PDMS. Recently, a 3D printer kit based on Fuse-deposition method (FDM) was modified to directly deposit hydrogel mold. The current study focuses on how to control the dispensing rate and the extruder motion of the 3D printer for this application. The paper presents a characterization process for determining optimal work ranges in terms of dispensing rate and the moving rate of the x-y table. Specifically, for a given hydrogel material and needle gauge, consistent dispensing volume rate was determined via varying the flow rate of syringe pump and analyzing recorded images. The ranges of the moving rate of the x-y table and the extrusion rate were then determined to generate the previous determined volume rate based on the experimental measurements. As the printer kit is controlled via open source software, the developed method will be applicable to characterization of depositing different material system.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

Multi-Layer Construction Process for Fabricating Electrospun Fiber Embedded Microfluidic Devices

2015 ◽  
Author(s):  
Karen Chang Yan ◽  
John Sperduto ◽  
Michael Rossini ◽  
Michael Sebok
Keyword(s):  
Biomedical Applications ◽  
Electrospun Fiber ◽  
Microfluidic Devices ◽  
Construction Process ◽  
Preliminary Results ◽  
Device Optimization ◽  
Specialized Equipment ◽  
Microfabrication Techniques

Microfluidic devices are widely used in biomedical applications owing to their inherent advantages. Microfabrication techniques are common methods for fabricating microfluidic devices, which require specialized equipment. This paper presents a multi-layer construction process for producing microfluidic devices via integrating two accessible fabrication techniques — hydrogel molding, a microfabrication-free method, and electrospinning (ES). The formed microchannels were examined via analyzing micrographs. Preliminary results demonstrate the feasibility of the method and potential for incorporating complex channels and device optimization.

scholarly journals Measurement and control of pressure driven flows in microfluidic devices using an optofluidic flow sensor

2014 ◽  
Vol 8 (5) ◽  
pp. 054123 ◽  
Author(s):  
Mohammad Sadegh Cheri ◽  
Hamidreza Shahraki ◽  
Jalal Sadeghi ◽  
Mohammadreza Salehi Moghaddam ◽  
Hamid Latifi
Keyword(s):  
Microfluidic Devices ◽  
Flow Sensor ◽  
And Control ◽  
Measurement And Control ◽  
Pressure Driven

Thermal Conductivity Performance Modeling and Characterization of a Novel Anisotropic Conductive Adhesive Used in Lead-Free Electronics Packaging

2012 ◽  
Author(s):  
Matthew J. Combs ◽  
S. Manian Ramkumar ◽  
Satish Kandlikar
Keyword(s):  
Thermal Conductivity ◽  
Base Material ◽  
Bond Line ◽  
Thermal Interface Material ◽  
The Novel ◽  
Conductive Adhesives ◽  
Curing Conditions ◽  
Bond Line Thickness ◽  
Significant Research ◽  
American Society

The continued desire to utilize an alternative to lead-based solder materials for electrical interconnections has led to significant research interest in Anisotropic Conductive Adhesives (ACAs). The use of ACAs in electrical connections creates bonds using a combination of metal particles and epoxies to replace solder. The novel ACA discussed in this paper allows for bonds to be created through aligning columns of conductive particles along the Z-axis. These columns are formed by the application of a magnetic field, during the curing process. The benefit of this novel ACA is that it does not require precise printing of the adhesive on pads and also enables the mass curing without creating shorts in the circuitry. This paper will present the findings of the thermal conductivity performance tests using the novel ACA and its applicability as a thermal interface material and for assembling bottom termination components, power devices, etc. The columns that act as electrical conduction paths also contribute towards the thermal conductivity. The thermal conductivity of the novel ACA was measured utilizing a system that is similar to that in ASTM (American Society of Testing Materials) D5470 standard. The goal was to examine the influence of Bond Line Thickness (BLT), particle loading densities, particle diameters and adhesive matrix curing conditions on the electrical and thermal performance of the novel ACA. This paper will also present a numerical model to describe the thermal behavior of the novel ACA. The novel ACA’s applicability for PCB-level assembly has also been successfully demonstrated by RIT, including base material characterization, effect of process parameters, failures, and long-term reliability. Reliability testing included the investigation of the assembly performance in temperature and humidity aging, thermal aging, air-to-air thermal cycling, and drop testing.

Biosolids odor reduction by solids inventory management in the secondary activated sludge treatment system

2009 ◽  
Vol 59 (2) ◽  
pp. 241-247 ◽  
Author(s):  
K. Sekyiamah ◽  
H. Kim
Keyword(s):  
Activated Sludge ◽  
Inventory Management ◽  
Process Parameters ◽  
Treatment Plant ◽  
Treatment System ◽  
Sludge Treatment ◽  
System A ◽  
Treatment Processes ◽  
Dominant Process ◽  
And Control

A wastewater treatment plant consists of unit processes designed to achieve specific waste reduction goals. Offensive odors associated with these treatment processes are a constant source of public complaints. The purpose of this study was to statistically determine the process parameters that influence the formation of volatile sulfur compounds (VSCs) in the secondary treatment system. A statistical model was developed to relate the process parameters to the formation of VSCs in this system. The model established that F/M ratio, sludge blanket depth and SSV60 were the dominant process parameters that influenced the formation of VSCs in the secondary sedimentation basin. This model provides a useful tool for plant engineers to predict and control the VSC formation in a secondary activated sludge treatment system.

scholarly journals An Innovative Welding Solution For Polymer Films in Packaging: Effect of Process Parameters

2021 ◽  
Author(s):  
Queen Tannous ◽  
Yves Bereaux ◽  
Pierre Mousseau ◽  
Anaïs Barasinski ◽  
Rémi Deterre ◽  
...  
Keyword(s):  
Process Parameters ◽  
Polymer Films ◽  
Welding Process ◽  
Rotational Frequency ◽  
Welding Interface ◽  
Optimization And Control ◽  
And Control ◽  
Future Work ◽  
Influential Parameters

In this paper, we present an innovative welding process for packaging applications developed by SEALESTER Company. For polymer films, studies have revealed that the welding interface must reach a specific temperature, known as “sealing initiation temperature”, to obtain a sealed joint. In this paper, we will be studying the effect of the process parameters on the evolution of temperature at the welding interface. For this purpose, thermocouples have been placed between the films at different points of the trajectory to measure the temperature evolution. Process parameters and temperature measurements were recorded in each experiment. Results show that the most influential parameters are the temperature and the linear velocity of the tool. Rotational frequency affects the heat distribution on the sealing surface. A minimum pressure must be applied. In conclusion, this new process can produce sealed polymer packages. Future work will consist of studying the quality of obtained seal in addition to optimization and control of the process.

scholarly journals Getting started with open-hardware: Development and control of microfluidic devices

2014 ◽  
Vol 35 (16) ◽  
pp. 2370-2377 ◽  
Author(s):  
Eric Tavares da Costa ◽  
Maria F. Mora ◽  
Peter A. Willis ◽  
Claudimir L. do Lago ◽  
Hong Jiao ◽  
...  
Keyword(s):  
Microfluidic Devices ◽  
Open Hardware ◽  
Hardware Development ◽  
And Control
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