A low‐cost cryogenic temperature controller for a VG ESCALAB V system

A thermal cycler is used to amplify segments of DNA using the polymerase chain reaction (PCR). It is an instrument that requires precise temperature control and rapid temperature changes for certain experimental protocols. However, the commercial thermal cyclers are still bulky, expensive and limited for laboratory use only. As such it is difficult for on-site molecular screening and diagnostics. In this work, a portable and low cost thermal cycler was designed and developed. The thermal cycler block was designed to fit six microcentrifuge tubes. A Proportional-Integral temperature controller was used to control the thermal cycler block temperature. The results showed that the maximum temperature ramp rate of the developed thermal cycler was 5.5 °C/s. The proportional gain (Kp) and integral gain (Ki) of the PI controller were 15 A/V and 1.8 A/Vs respectively. Finally, the developed thermal cycler successfully amplified six DNA samples at the expected molecular weight of 150 base pair. It has been validated using the Eppendorf Mastercycler nexus gradient system and gel electrophoresis analysis

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Design and Construction of Low Temperature Attachment for Commercial AFM

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.209.137 ◽

2013 ◽

Vol 209 ◽

pp. 137-142

Author(s):

Abrarkhan M. Pathan ◽

Dhawal H. Agrawal ◽

Pina M. Bhatt ◽

Hitarthi H. Patel ◽

U.S. Joshi

Keyword(s):

Atomic Force Microscope ◽

Cryogenic Temperature ◽

Low Cost ◽

Perovskite Manganite ◽

Atomic Force ◽

Structure Of Nanomaterials ◽

Negative Bending ◽

Set Up ◽

Free Environment ◽

Repulsive Forces

With the rapid advancements in the field of nanoscience and nanotechnology, scanning probe microscopy has become an integral part of a typical R&D lab. Atomic force microscope (AFM) has become a familiar name in this category. The AFM measures the forces acting between a fine tip and a sample. The tip is attached to the free end of a cantilever and is brought very close to a surface. Attractive or repulsive forces resulting from interactions between the tip and the surface will cause a positive or negative bending of the cantilever. The bending is detected by means of a laser beam, which is reflected from the backside of the cantilever. Atomic force microscopy is currently applied to various environments (air, liquid, vacuum) and types of materials such as metal semiconductors, soft biological samples, conductive and non-conductive materials. With this technique size measurements or even manipulations of nano-objects may be performed. An experimental setup has been designed and built such that a commercially available Atomic Force Microscope (AFM) (Nanosurf AG, Easyscan 2) can be operated at cryogenic temperature under vacuum and in a vibration-free environment. The design also takes care of portability and flexibility of AFM i.e. it is very small, light weight and AFM can be used in both ambient and cryogenic conditions. The whole set up was assembled in-house at a fairly low cost. It is used to study the surface structure of nanomaterials. Important perovskite manganite Pr0.7Ca0.3MnO3thin films were studied and results such as morphology, RMS area and line roughness as well as the particle size have been estimated at cryogenic temperature.

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Low Cost, Open-Loop Temperature Controller for MEMS and Modular Microfluidics Applications

Volume 11: Nano and Micro Materials, Devices and Systems; Microsystems Integration ◽

10.1115/imece2011-65543 ◽

2011 ◽

Author(s):

Brooks B. Lowrey ◽

Christopher R. Brown ◽

Daniel S. Park ◽

Michael C. Murphy

Keyword(s):

Low Cost ◽

Open Loop ◽

Thermal Reactor ◽

Temperature Controller ◽

Thermally Responsive ◽

Channel Temperature ◽

Temperature Boundary ◽

In Series ◽

Commercial Off The Shelf ◽

Model C

A commercially manufactured thermostat (Model C Thermostat, Portage Electronic Products Inc., North Canton, OH) was employed as a precision MEMS temperature controller for a simulated continuous flow thermal reactor, with three temperature zones to mimic a polymerase chain reaction (CFPCR) device but different temperature set points to allow use of off-the-shelf controllers and thermally-responsive fluids. The ability of the commercial thermostats to maintain the temperatures within given tolerance bands in the thermal reactor was investigated. The factory supplied and calibrated thermostats were actuated by trimetallic strips, and supplied in a normally-closed configuration. Each thermostat was arranged in series with a 28 VDC power supply, a Kapton heater, and an aluminum thermal block to establish a constant temperature boundary condition for each temperature zone. Calibration temperatures for each thermostat reflected the three temperature set points of the simulated PCR device in the testing apparatus. Temperatures were collected by fixing Type K thermocouples in the fluidic channels of the simulated PCR device, and recording the temperature over time. The commercial, off-the-shelf, open-loop controllers successfully maintained ±1°C tolerance bands within each thermal zone. The ±1°C variation in the channel temperature was caused by the chatter due to the switching of the thermostat.

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High-precision low-cost temperature controller

Journal of Physics E Scientific Instruments ◽

10.1088/0022-3735/11/7/025 ◽

1978 ◽

Vol 11 (7) ◽

pp. 692-696 ◽

Cited By ~ 16

Author(s):

M Grubic ◽

U Wurz

Keyword(s):

High Precision ◽

Low Cost ◽

Temperature Controller

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Investigation on Effect of Cryogenic Temperature on Mechanical Behavior of Jute and Hemp Fibers Reinforced Polymer Composites

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.895.76 ◽

2019 ◽

Vol 895 ◽

pp. 76-82 ◽

Cited By ~ 1

Author(s):

B. Vinod ◽

L.J. Sudev

Keyword(s):

Polymer Composites ◽

Polymer Matrix ◽

Cryogenic Temperature ◽

Low Cost ◽

Cryogenic Treatment ◽

Natural Fibers ◽

Fiber Material ◽

Hybrid Fibers ◽

Impact Properties ◽

Hemp Fibers

In past few decades, natural fibers which are viable and abundant in nature are the emerging trends in material science as reinforcement for polymer matrix materials and they are the commute for the non-biodegradable, non-renewable and high-density synthetic fibers. Plant-based fibers such as banana, hemp, kenaf, PALF, jute, and coir has been used as reinforcement in a polymer matrix for the applications in consumer goods, furniture’s, civil and automotive structures and low-cost housing structures. The natural fibers used in this study are Hemp and Jute fibers which are finding increasing in the composite material as reinforcements. The main objective of the current work is to examine the mechanical properties of hybrid fibers (hemp and jute) reinforced epoxy composites under room temperature and at cryogenic temperature. From this study, it is clear that tensile, flexural and impact properties of polymer composites are greatly influenced by cryogenic temperature and its properties vary with respect to the extent of cryogenic treatment. The specimens are immersed in liquid nitrogen for the duration of 15, 30, 45 and 60mins and later it is subjected for tensile, flexural and impact properties. The maximum tensile strength of 21.13MPa, flexural strength of 51.95MPa and Impact strength of 8.935kJ/m2 is obtained for an untreated specimen and its value start to decrease as curing time increases. At cryogenic temperature, the material comes harder and loses its ductile property and become brittle due differ in thermal expansion coefficient of matrix and fiber material

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