Low-cost photolithography system for cell biology labs

Abstract Soft lithography, a tool widely applied in biology and life sciences with numerous applications, uses the soft molding of photolithography-generated master structures by polymers. The central part of a photolithography set-up is a mask-aligner mostly based on a high-pressure mercury lamp as an ultraviolet (UV) light source. This type of light source requires a high level of maintenance and shows a decreasing intensity over its lifetime, influencing the lithography outcome. In this paper, we present a low-cost, bench-top photolithography tool based on ninety-eight 375 nm light-emitting diodes (LEDs). With approx. 10 W, our presented lithography set-up requires only a fraction of the energy of a conventional lamp, the LEDs have a guaranteed lifetime of 1000 h, which becomes noticeable by at least 2.5 to 15 times more exposure cycles compared to a standard light source and with costs less than 850 C it is very affordable. Such a set-up is not only attractive to small academic and industrial fabrication facilities who want to enable work with the technology of photolithography and cannot afford a conventional set-up, but also microfluidic teaching laboratories and microfluidic research and development laboratories, in general, could benefit from this cost-effective alternative. With our self-built photolithography system, we were able to produce structures from 6 μm to 50 μm in height and 10 μm to 200 μm in width. As an optional feature, we present a scaled-down laminar flow hood to enable a dust-free working environment for the photolithography process.

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A low-cost low-maintenance ultraviolet lithography light source based on light-emitting diodes

Lab on a Chip ◽

10.1039/c4lc00472h ◽

2015 ◽

Vol 15 (1) ◽

pp. 57-61 ◽

Cited By ~ 16

Author(s):

M. Erickstad ◽

E. Gutierrez ◽

A. Groisman

Keyword(s):

Light Source ◽

Light Emitting Diodes ◽

Uv Light ◽

Low Cost ◽

Uniform Illumination ◽

Large Area ◽

Ultraviolet Lithography ◽

Light Emitting

An LED-based UV-light source producing collimated uniform illumination over a large area is built and used to fabricate PDMS microchannels with near-rectangular profiles and depths up to 300 μm.

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Cost-Effective Directional Drilling and Logging-While-Drilling Operational/Maintenance Model Aids an East Africa Operator to Deliver Its Remote Location Exploration Campaign

10.2118/afrc-2582954-ms ◽

2016 ◽

Author(s):

Iain Lunney

Keyword(s):

Low Cost ◽

Commodity Prices ◽

Cost Effective ◽

Directional Drilling ◽

Remote Maintenance ◽

Support Team ◽

High Level ◽

Remote Assistance ◽

Level Of Experience ◽

Maintenance Model

ABSTRACT In a cost-sensitive market driven by depressed commodity prices, significant capital challenges exist for operators interested in pursuing exploration activities in remote environments to define their producible reserves. This paper explores the organizational and operational model developed by a service company over several remote area mobilizations; this model resulted in an optimized low-cost service delivery model characterized by top quartile operational key performance indicators (KPIs). The model centralizes critical functions of an operational organization into discrete service units that are located near the operational location or that provide remote assistance with communication and reporting lines in place to function effectively. Top quartile operational performance and tool availability is a result of placing a remote repair and maintenance facility that includes containerized specialty modules near the operational area. The upfront bottomhole assembly engineering, 24/7 monitoring, and proactive feedback of logged data, drillstring dynamics, and wellbore hydraulics are performed by a core team of subject matter experts in their respective disciplines from an established centralized operating center. The operational KPIs over the course of the six well exploration campaign provided substantial evidence to support the reliability of the model and the high level of experience used in both the remote maintenance facility and the operations center support team.

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A Very Low-Cost, Labor-Efficient, and Simple Method to Block Scattered Ultraviolet Light in PDMS Microfluidic Devices by Inserting Aluminum Foil Strips

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4041436 ◽

2018 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Shuo Wang ◽

Peter Shankles ◽

Scott Retterer ◽

Yong Tae Kang ◽

Chang Kyoung Choi

Keyword(s):

Soft Lithography ◽

Uv Light ◽

Low Cost ◽

Microfluidic Devices ◽

Aluminum Foil ◽

Material Synthesis ◽

Simple Method ◽

Micro Particles ◽

Complex Shapes ◽

The Cost

Abstract Opto-microfluidic methods have advantages for manufacturing complex shapes or structures of micro particles/hydrogels. Most of these microfluidic devices are made of polydimethylsiloxane (PDMS) by soft lithography because of its flexibility of designing and manufacturing. However, PDMS scatters ultraviolet (UV) light, which polymerizes the photocrosslinkable materials at undesirable locations and clogs the microfluidic devices. A fluorescent dye has previously been employed to absorb the scattered UV light and shift its wavelength to effectively solve this issue. However, this method is limited due to the cost of the materials (tens of dollars per microchip), the time consumed on synthesizing the fluorescent material and verifying its quality (two to three days). More importantly, significant expertise on material synthesis and characterization is required for users of the opto-microfluidic technique. The cost of preliminary testing on multiple iterations of different microfluidic chip designs would also be excessive. Alternatively, with a delicate microchannel design, we simply inserted aluminum foil strips (AFS) inside the PDMS device to block the scattered UV light. By using this method, the UV light was limited to the exposure region so that the opto-microfluidic device could consistently generate microgels longer than 6 h. This is a nearly cost- and labor-free method to solve this issue.

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Phase-Change Heat Transfer Measurements Using Temperature-Sensitive Paints

Journal of Heat Transfer ◽

10.1115/1.4038135 ◽

2017 ◽

Vol 140 (3) ◽

Cited By ~ 5

Author(s):

Husain Al Hashimi ◽

Caleb F. Hammer ◽

Michel T. Lebon ◽

Dan Zhang ◽

Jungho Kim

Keyword(s):

Heat Transfer ◽

High Speed ◽

Uv Light ◽

Flow Boiling ◽

Low Cost ◽

Data Interpretation ◽

Temperature Sensitive ◽

Time Resolved ◽

Light Emitting ◽

Phase Change Heat Transfer

Techniques based on temperature-sensitive paints (TSP) to measure time-resolved temperature and heat transfer distributions at the interface between a wall and fluid during pool and flow boiling are described. The paints are excited using ultraviolet (UV) light emitting diodes (LEDs), and changes in fluorescence intensity are used to infer local temperature differences across a thin insulator from which heat flux distribution is obtained. Advantages over infrared (IR) thermometry include the ability to use substrates that are opaque to IR (e.g., glass, plexiglass and plastic films), use of low-cost optical cameras, no self-emission from substrates to complicate data interpretation, high speed, and high spatial resolution. TSP-based methods to measure wall heat transfer distributions are validated and then demonstrated for pool and flow boiling.

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Low Cost Cooling Device for High Power LED Lamps

Volume 11: Heat Transfer and Thermal Engineering ◽

10.1115/imece2020-24630 ◽

2020 ◽

Author(s):

Pamela Martinez-Vega ◽

Araceli Lopez-Badillo ◽

J. Luis Luviano-Ortiz ◽

Abel Hernandez-Guerrero ◽

Jaime G. Cervantes

Keyword(s):

Reference Model ◽

Light Emitting Diode ◽

Low Cost ◽

Cost Effective ◽

Heat Sinks ◽

Modern World ◽

Type Model ◽

Light Emitting

Abstract The modern world progressively demands more energy; according to forecasts energy consumption will grow at an average annual rate of 3 percent. Therefore, it is necessary to purchase products or devices that are efficient and environmentally friendly. Technology in LED (Light Emitting Diode) lighting is presented as an alternative to energy saving, since LEDs have proven to be extremely efficient, have a long service life and their cost-effective ratio is very good. However, the heat emitted by the LED chip must be dissipated effectively, since the overheating of the chip reduces the efficiency and lifetime of the lamp. Therefore, heat sinks that are reliable, efficient and inexpensive should be designed and built. The present work proposes new designs for heat sinks in LED lamps, some of the models in the design of the fins refer to the Fibonacci series. The models proposed in the present work that have a significant advantage are the Type 1E Model (5.2% mass savings and better thermal efficiency of 8.33%), GR Type 1 Model (3.12% lighter and 3.33% more efficient) and the GRL Type Model (4. 51% mass savings and 5.55% thermally more efficient) compared to the Type 2 Reference Model proposed by Jang et al. [12].

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1.331μm Narrow-Bandwidth Light Source Based on Polymer Micro-Blazed Grating

2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems ◽

10.1115/micronano2008-70207 ◽

2008 ◽

Cited By ~ 1

Author(s):

Hairong Wang ◽

Xianni Gao ◽

Guoliang Sun ◽

Yulong Zhao ◽

Zhuangde Jiang

Keyword(s):

Light Source ◽

Light Emitting Diode ◽

Low Cost ◽

Diffraction Order ◽

Blazed Grating ◽

Light Emitting ◽

Led Light ◽

Narrow Bandwidth ◽

Narrow Width ◽

The Cost

In order to detect methane (CH4) accurately and reliably, this paper presents a sensor which consists of infrared diode, fixtures, blazed grating, to realize the extremely narrow-bandwidth light at wavelength of 1.331μm. Based on factors such as compatibility with the transmission characteristics of silica fiber and the cost, a LED (light-emitting diode) with center wavelength of 1.3μm is selected. The LED light is modulated as the parallel light beam. As the light is incident in a micro-blazed grating with certain angle, by diffraction and interference, the light will output the maximum light intensity of its diffraction order at 1.331 μm, which just is an absorption peak of CH4. Micro-blazed grating applied here is low cost and easy replication by various ways, which makes extreme narrow width wavelength possible. Simulation and analysis indicate the designed prototype can output 1.331μm with bandwidth from 1.32907μm to 1.332495μm. With the light source basing on light dividing system, more reliable and higher sensitive measurement of the dangerous gases such as methane and carbon monoxide (CO) can be realized.

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Light-Emitting-Diode-Based Multispectral Photoacoustic Computed Tomography System

Sensors ◽

10.3390/s19224861 ◽

2019 ◽

Vol 19 (22) ◽

pp. 4861 ◽

Cited By ~ 8

Author(s):

Sumit Agrawal ◽

Christopher Fadden ◽

Ajay Dangi ◽

Xinyi Yang ◽

Hussain Albahrani ◽

...

Keyword(s):

Computed Tomography ◽

Molecular Imaging ◽

Photoacoustic Imaging ◽

Light Emitting Diode ◽

Low Cost ◽

Tunable Laser ◽

Cost Effective ◽

Light Emitting ◽

Multi Wavelength ◽

Human Finger

Photoacoustic computed tomography (PACT) has been widely explored for non-ionizing functional and molecular imaging of humans and small animals. In order for light to penetrate deep inside tissue, a bulky and high-cost tunable laser is typically used. Light-emitting diodes (LEDs) have recently emerged as cost-effective and portable alternative illumination sources for photoacoustic imaging. In this study, we have developed a portable, low-cost, five-dimensional (x, y, z, t, λ ) PACT system using multi-wavelength LED excitation to enable similar functional and molecular imaging capabilities as standard tunable lasers. Four LED arrays and a linear ultrasound transducer detector array are housed in a hollow cylindrical geometry that rotates 360 degrees to allow multiple projections through the subject of interest placed inside the cylinder. The structural, functional, and molecular imaging capabilities of the LED–PACT system are validated using various tissue-mimicking phantom studies. The axial, lateral, and elevational resolutions of the system at 2.3 cm depth are estimated as 0.12 mm, 0.3 mm, and 2.1 mm, respectively. Spectrally unmixed photoacoustic contrasts from tubes filled with oxy- and deoxy-hemoglobin, indocyanine green, methylene blue, and melanin molecules demonstrate the multispectral molecular imaging capabilities of the system. Human-finger-mimicking phantoms made of a bone and blood tubes show structural and functional oxygen saturation imaging capabilities. Together, these results demonstrate the potential of the proposed LED-based, low-cost, portable PACT system for pre-clinical and clinical applications.

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Cost-Effective Light-Mixing Module for Solar-Lighting System Appended With Auxiliary RGBW Light-Emitting Diodes

Journal of Solar Energy Engineering ◽

10.1115/1.4037746 ◽

2017 ◽

Vol 139 (6) ◽

Author(s):

An Chi Wei ◽

Shih Chieh Lo ◽

Ju-Yi Lee ◽

Hong-Yih Yeh

Keyword(s):

Light Source ◽

Light Emitting Diodes ◽

Cylindrical Tube ◽

Cost Effective ◽

Lighting System ◽

Optical Efficiency ◽

Light Emitting ◽

Solar Lighting ◽

Lighting Systems ◽

Main Components

A light-mixing module consisting of a compound parabolic concentrator (CPC) and a light-mixing tube is proposed herein to realize a uniform and efficient solar-lighting system. In this lighting system, the sunlight collected into a fiber and then guided to an indoor destination is the principal light source, while an auxiliary light source including multiple red, green, blue, and white (RGBW) light-emitting diodes (LEDs) is controlled by an auto-compensating module. To mix the principal and the auxiliary sources and to realize the uniform illumination, the light-mixing tube was coated with BaSO4 and optimized as a cylindrical tube. The design of the light-mixing tube is described and discussed in this article. According to the simulated results, the uniformity and the optical efficiency of the designed light-mixing tube are 82.9% and 85.7%, respectively, while from the experimental results, the uniformity of 85.9% and the optical efficiency of 83.3% have been obtained. In terms of the common indoor-lighting standards and the specifications of commercial components used in lighting systems, the proposed light-mixing module has demonstrated the high uniformity and acceptable optical efficiency. Additionally, since the main components of the light-mixing module can be designed as plastic optics, a cost-effective light-mixing module and a profitable lighting system can be realized. Thus, the performance and the price of the proposed light-mixing module fit the demands of the illumination market, while the proposed system shows the potential for indoor solar-lighting applications.

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