Design of Precision Hot Embossing Machine for Micro-Patterning on PMMA

Author(s):  
Sridhar P ◽  
Supreet Singh Bahga ◽  
Jitendra P. Khatait

Abstract A microfluidic chip requires micro-channels to be created on a substrate. This paper focuses on the design and development of a precision hot embossing machine for replication of microstructures on a PMMA substrate. Kinematic coupling using three spherical balls in radial v-grooves is used to achieve precise positioning of the mold insert with the base. Flexure based parallel guidance mechanism is used for one DOF motion required for the embossing process. The mechanism allows the motion of the mold normal to the substrate surface. Flexure based kinematic coupling with the thermal center is designed to mitigate thermal stress build-up during heating and cooling of the mold insert. An Arduino-based micro-controller is developed to control the temperature profile during the process. A prototype is fabricated and experiments are performed with an aluminium mold insert on a PMMA substrate. The result shows the feasibility of the concept and the set-up can be used to develop a cost-effective precision hot embossing machine for creating micro-patterns for microfluidic applications.


Author(s):  
Glenn Conner ◽  
Devanda Lek ◽  
Juan A. Gomez ◽  
In-Hyouk Song ◽  
Taehyun Park ◽  
...  

A cost effective alignment and positioning system was developed for double-sided hot embossing processes using kinematic principles. Alignment tooling located and transferred the top mold insert location to the proper location for the complementary mold insert and hot embossing was performed. The samples were checked for alignment accuracy and consistency. Adjustments were made and sampling repeated and measured. Results showed the alignment system can improve the locating and positioning of the complementary mold insert in relation to the top in a repeatable and cost effective manner.



Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 116
Author(s):  
Julian Deuerling ◽  
Shaun Keck ◽  
Inasya Moelyadi ◽  
Jens-Uwe Repke ◽  
Matthias Rädle

This work presents a novel method for the non-invasive, in-line monitoring of mixing processes in microchannels using the Raman photometric technique. The measuring set-up distinguishes itself from other works in this field by utilizing recent state-of-the-art customized photon multiplier (CPM) detectors, bypassing the use of a spectrometer. This addresses the limiting factor of integration times by achieving measuring rates of 10 ms. The method was validated using the ternary system of toluene–water–acetone. The optical measuring system consists of two functional units: the coaxial Raman probe optimized for excitation at a laser wavelength of 532 nm and the photometric detector centered around the CPMs. The spot size of the focused laser is a defining factor of the spatial resolution of the set-up. The depth of focus is measured at approx. 85 µm with a spot size of approx. 45 µm, while still maintaining a relatively high numerical aperture of 0.42, the latter of which is also critical for coaxial detection of inelastically scattered photons. The working distance in this set-up is 20 mm. The microchannel is a T-junction mixer with a square cross section of 500 by 500 µm, a hydraulic diameter of 500 µm and 70 mm channel length. The extraction of acetone from toluene into water is tracked at an initial concentration of 25% as a function of flow rate and accordingly residence time. The investigated flow rates ranged from 0.1 mL/min to 0.006 mL/min. The residence times from the T-junction to the measuring point varies from 1.5 to 25 s. At 0.006 mL/min a constant acetone concentration of approx. 12.6% was measured, indicating that the mixing process reached the equilibrium of the system at approx. 12.5%. For prototype benchmarking, comparative measurements were carried out with a commercially available Raman spectrometer (RXN1, Kaiser Optical Systems, Ann Arbor, MI, USA). Count rates of the spectrophotometer surpassed those of the spectrometer by at least one order of magnitude at identical target concentrations and optical power output. The experimental data demonstrate the suitability and potential of the new measuring system to detect locally and time-resolved concentration profiles in moving fluids while avoiding external influence.



Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 661
Author(s):  
Luigi Piazzi ◽  
Stefano Acunto ◽  
Francesca Frau ◽  
Fabrizio Atzori ◽  
Maria Francesca Cinti ◽  
...  

Seagrass planting techniques have shown to be an effective tool for restoring degraded meadows and ecosystem function. In the Mediterranean Sea, most restoration efforts have been addressed to the endemic seagrass Posidonia oceanica, but cost-benefit analyses have shown unpromising results. This study aimed at evaluating the effectiveness of environmental engineering techniques generally employed in terrestrial systems to restore the P. oceanica meadows: two different restoration efforts were considered, either exploring non-degradable mats or, for the first time, degradable mats. Both of them provided encouraging results, as the loss of transplanting plots was null or very low and the survival of cuttings stabilized to about 50%. Data collected are to be considered positive as the survived cuttings are enough to allow the future spread of the patches. The utilized techniques provided a cost-effective restoration tool likely affordable for large-scale projects, as the methods allowed to set up a wide bottom surface to restore in a relatively short time without any particular expensive device. Moreover, the mats, comparing with other anchoring methods, enhanced the colonization of other organisms such as macroalgae and sessile invertebrates, contributing to generate a natural habitat.



Author(s):  
Roger Hitchin

Policies to reduce carbon emissions are leading to substantial changes in the demand for electricity and to the structure of electricity supply systems, which will alter the cost structure of electricity supply. This can be expected to result in corresponding changes to the price structure faced by customers. This note is an initial exploration of how possible new price structures may impact on HVAC system and building design and use. Changes in the price structure of electricity supply (separately from changes in price levels) can significantly affect the cost-effective design and operation of building services systems; especially of heating and cooling systems. The nature and implications of these changes can have important implications for future system design and operation.



Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Peio Ziarsolo ◽  
Tomas Hasing ◽  
Rebeca Hilario ◽  
Victor Garcia-Carpintero ◽  
Jose Blanca ◽  
...  

Abstract Background K-seq, a new genotyping methodology based on the amplification of genomic regions using two steps of Klenow amplification with short oligonucleotides, followed by standard PCR and Illumina sequencing, is presented. The protocol was accompanied by software developed to aid with primer set design. Results As the first examples, K-seq in species as diverse as tomato, dog and wheat was developed. K-seq provided genetic distances similar to those based on WGS in dogs. Experiments comparing K-seq and GBS in tomato showed similar genetic results, although K-seq had the advantage of finding more SNPs for the same number of Illumina reads. The technology reproducibility was tested with two independent runs of the tomato samples, and the correlation coefficient of the SNP coverages between samples was 0.8 and the genotype match was above 94%. K-seq also proved to be useful in polyploid species. The wheat samples generated specific markers for all subgenomes, and the SNPs generated from the diploid ancestors were located in the expected subgenome with accuracies greater than 80%. Conclusion K-seq is an open, patent-unencumbered, easy-to-set-up, cost-effective and reliable technology ready to be used by any molecular biology laboratory without special equipment in many genetic studies.



2021 ◽  
Vol 13 (9) ◽  
pp. 4651
Author(s):  
Ming-Lun Alan Fong

The analysis of ventilation strategies is fundamentally affected by regional climate conditions and local cost databases, in terms of energy consumption, CO2 emission and cost-effective analysis. A systematic approach is covered in this paper to estimate a local economic and environmental impact on a medium-sized space located in two regions during supply-and-installation and operation phases. Three ventilation strategies, including mixing ventilation (MV), displacement ventilation (DV) and stratum ventilation (SV) were applied to medium-sized air-conditioned space with this approach. The trend of the results for three ventilation systems in the life cycle assessment (LCA) and life cycle cost (LCC) analysis is SV < DV < MV. The result of CO2 emission and regional LCC shows that SV is the lowest one in both regional studies. In comparison with the Hong Kong Special Administrative Region (HKSAR) during 20 Service years, the case analysis demonstrates that the percentage differences in LCC analysis of MV, DV & SV in Guangdong are less than 20.5%, 19.4% and 18.82% respectively. Their CO2 emission of MV, DV and SV in Guangdong are more than HKSAR in 10.69%, 11.22% and 12.05%, respectively. The present study could provide information about regional effects in the LCA and LCC analysis of three ventilation strategies emissions, and thereby help set up models for decision-making on high efficiency and cost-effective ventilation strategy plans.



2001 ◽  
Vol 35 (4) ◽  
pp. 33-45 ◽  
Author(s):  
Peter Hogarth

Between 23rd and 25th July 2001 GeoSwath, a high specification shallow water wide swath bathymetry system, was used to survey the entire Portsmouth NH Harbor area. This paper deals with the results of this survey, illustrating the potential for significant reductions in the high costs, which have prevented widespread proliferation of Swath Bathymetry systems to date. Data, including a complete DTM gridded to 1 m resolution, will be presented and discussed in detail. These results show that the system is very easy to set up and use, requires greatly reduced boat and processing time, whilst offering high accuracy and very high coverage and resolution when used in a real-world survey of a dynamic harbor environment.



Author(s):  
Anmol Arora ◽  
Andrew Wright ◽  
Mark Cheng ◽  
Zahra Khwaja ◽  
Matthew Seah

AbstractHealthcare as an industry is recognised as one of the most innovative. Despite heavy regulation, there is substantial scope for new technologies and care models to not only boost patient outcomes but to do so at reduced cost to healthcare systems and consumers. Promoting innovation within national health systems such as the National Health Service (NHS) in the United Kingdom (UK) has been set as a key target for health care professionals and policy makers. However, while the UK has a world-class biomedical research industry, several reports in the last twenty years have highlighted the difficulties faced by the NHS in encouraging and adopting innovations, with the journey from idea to implementation of health technology often taking years and being very expensive, with a high failure rate. This has led to the establishment of several innovation pathways within and around the NHS, to encourage the invention, development and implementation of cost-effective technologies that improve health care delivery. These pathways span local, regional and national health infrastructure. They operate at different stages of the innovation pipeline, with their scope and work defined by location, technology area or industry sector, based on the specific problem identified when they were set up. In this introductory review, we outline each of the major innovation pathways operating at local, regional and national levels across the NHS, including their history, governance, operating procedures and areas of expertise. The extent to which innovation pathways address current challenges faced by innovators is discussed, as well as areas for improvement and future study.



2001 ◽  
Author(s):  
Hyoung-In Lee ◽  
Hye-Jung Cho ◽  
In-Seob Song ◽  
Ju-Hyeong Lee

Abstract Cooling of electronic components is often limited by space availability and power consumption. Capillary-pumped loops (CPL) are utilized to achieve a coolant circulation via self-activated capillarity (Faghri, 1995). However, CPL is extremely unstable due to a nonlinear feedback among capillarity, viscous force, and heat transfer. Conventional refrigeration theories, which usually allow a larger pressure jump due to an external pumping, failed to explain the CPL cycle. The dynamics of a flow through a CPL cooling cycle is investigated with a particular attention to the flow in the micro-channels. Full numerical approaches, by which multi-component multi-phase flows are solved, tend to obscure the engineers from identifying outstanding design parameters. Instead, one here adopts several simplified semi-analyitic approaches, namely, models based on single-phase flows with discrete zones of heating and cooling. The analytical and numerical results could explain some general tendencies in the dynamical features like dry-out and flooding. However, the problem still requires closer and more realistic modeling.



COVID ◽  
2021 ◽  
Vol 1 (4) ◽  
pp. 717-727
Author(s):  
Parastoo Kheiroddin ◽  
Magdalena Gründl ◽  
Michael Althammer ◽  
Patricia Schöberl ◽  
Linda Plail ◽  
...  

(1) Background: With vaccination and new variants of SARS-CoV-2 on the horizon, efficient testing in schools may enable prevention of mass infection outbreaks, keeping schools safe places and buying time until decisions on feasibility and the necessity of vaccination in children and youth are made. We established, in the course of the WICOVIR (Where Is the COrona VIRus) study, that gargle-based pool-PCR testing offers a feasible, efficient, and safe testing system for schools in Germany when applied by central university laboratories. (2) Objectives: We evaluated whether this approach can be implemented in different rural and urban settings. (3) Methods: We assessed the arrangements required for successful implementation of the WICOVIR approach in a variety of settings in terms of transport logistics, data transfer and pre-existing laboratory set-up, as well as the time required to establish the set-up. (4) Results: We found that once regulatory issues have been overcome, all challenges pertaining to logistics, data transfer, and laboratory testing on different platforms can be solved within one month. Pooling and depooling of samples down to the individual test result were achievable within one working day in all settings. Local involvement of the community and decentralized set-ups were keys for success. (5) Conclusion: The WICOVIR gargle-based pool-PCR system is so robust and simple that it can be implemented within one month in all settings now or in future pandemics.



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