Experimental Study of Flexible Electrohydrodynamic Conduction Pumping for Electronics Cooling

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Nathaniel J. O'Connor ◽  
Alexander J. Castaneda ◽  
Pavolas N. Christidis ◽  
Nicolas Vayas Tobar ◽  
Michal Talmor ◽  
...  
Keyword(s):  
Flexible Electronics ◽  
Electronics Cooling ◽  
Thermal Control ◽  
Working Fluid ◽  
Stable Operation ◽  
Manufacturing Method ◽  
And Performance ◽  
And Control ◽  
First Time

Abstract As modern-day electronics develop, electronic devices become smaller, more powerful, and are expected to operate in more diverse configurations. However, the thermal control systems that help these devices maintain stable operation must advance as well to meet the demands. One such demand is the advent of flexible electronics for wearable technology, medical applications, and biology-inspired mechanisms. This paper presents the design and performance characteristics of flexible electrohydrodynamic (EHD) pumps, based on EHD conduction pumping technology in macro- and mesoscales. Unlike mechanical pumps, EHD conduction pumps have no moving parts, can be easily adjusted to the microscale, and have been shown to generate and control the flow of refrigerants for electronics cooling applications. However, these pumping devices have only been previously tested in rigid configurations unsuitable for use with flexible electronics. In this work, for the first time, the net flow generated by flexible EHD conduction pumps is measured on a flat plane in various configurations. In this study, the results show that the flexible EHD conduction pumps are capable of generating significant flow velocities in all size scales considered in this study, with and without bending. This study also proves the viability of screen printing as a manufacturing method for these pumps. The selection of working fluid for EHD conduction pumping is also a topic of discussion. Novec Engineered Fluids have been a popular choice for EHD pumping; however, long-term testing has shown that some Novec fluids degrade over time.

Experimental Study of Flexible Electrohydrodynamic Conduction Pumping for Electronics Cooling

2018 ◽  
Author(s):  
Nicolas Vayas Tobar ◽  
Pavolas N. Christidis ◽  
Nathaniel J. O'Connor ◽  
Michal Talmor ◽  
Jamal Seyed-Yagoobi
Keyword(s):  
Flexible Electronics ◽  
Electronics Cooling ◽  
Thermal Control ◽  
Stable Operation ◽  
Space Applications ◽  
Manufacturing Method ◽  
Micro Scale ◽  
Wide Range ◽  
And Performance ◽  
And Control

As modern day electronics develop, electronic devices become smaller, more powerful, and are expected to operate in more diverse configurations. However, the thermal control systems that help these devices maintain stable operation must advance as well to meet the demands. One such demand is the advent of flexible electronics for wearable technology, medical applications, and biology-inspired mechanisms. This paper presents the design and performance characteristics of a proof of concept for a flexible Electrohydrodynamic (EHD) pump, based on EHD conduction pumping technology in macro- and meso-scales. Unlike mechanical pumps, EHD conduction pumps have no moving parts, can be easily adjusted to the micro-scale, and have been shown to generate and control the flow of refrigerants for electronics cooling applications. However, these pumping devices have only been previously tested in rigid configurations unsuitable for use with flexible electronics. In this work, for the first time, the net flow generated by flexible EHD conduction pumps is measured on a flat-plane and in various bending configurations. In this behavioral characteristics study, the results show that the flexible EHD conduction pumps are capable of generating significant flow velocities in all size scales considered in this study, with and without bending. This study also proves the viability of screen printing as a manufacturing method for these pumps. EHD conduction pumping technology shows potential for use in a wide range of terrestrial and space applications, including thermal control of rigid as well as flexible electronics, flow generation and control in micro-scale heat exchangers and other thermal devices, as well as cooling of high power electrical systems, soft robotic actuators, and medical devices.

Mechanical Insertion and Reliability Testing of Thermal Interface Materials for Semiconductor Test and Burn-in Applications

2019 ◽  
Vol 2019 (1) ◽  
pp. 000584-000590
Author(s):  
Dave Saums ◽  
Tim Jensen ◽  
Carol Gowans ◽  
Seth Homer ◽  
Ron Hunadi
Keyword(s):  
Performance Test ◽  
Thermal Interface Materials ◽  
Test Procedures ◽  
Thermal Interface ◽  
Semiconductor Test ◽  
New Material ◽  
And Performance ◽  
And Control ◽  
Interface Materials

Abstract Very challenging requirements exist for thermal interface materials (TIMs) for demanding applications I semiconductor testing. Reliability requirements and multiple contact cycling requirements are substantially different and do not exist in traditional applications for TIMs. Developing new material types to meet these very exacting and unusual requirements has been a long-term goal and requires development of an unusual series of test procedures to demonstrate whether the desired reliability goals have been met. Use of a servo-driven, commercial test stand that has unique features for operation and control is described as the basis for a reliability and performance test program developed for these new materials in three phases, with new data for a fourth test phase added, and comparative values for material performance.

scholarly journals Impact of porcine cytomegalovirus on long-term orthotopic cardiac xenotransplant survival

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joachim Denner ◽  
Matthias Längin ◽  
Bruno Reichart ◽  
Luise Krüger ◽  
Uwe Fiebig ◽  
...  
Keyword(s):  
Immunosuppressive Regimen ◽  
Complete Loss ◽  
Orthotopic Heart Transplantation ◽  
Survival Times ◽  
Post Transplantation ◽  
Porcine Cytomegalovirus ◽  
And Control ◽  
First Time ◽  
Pai 1

Abstract Xenotransplantation using pig organs has achieved survival times up to 195 days in pig orthotopic heart transplantation into baboons. Here we demonstrate that in addition to an improved immunosuppressive regimen, non-ischaemic preservation with continuous perfusion and control of post-transplantation growth of the transplant, prevention of transmission of the porcine cytomegalovirus (PCMV) plays an important role in achieving long survival times. For the first time we demonstrate that PCMV transmission in orthotopic pig heart xenotransplantation was associated with a reduced survival time of the transplant and increased levels of IL-6 and TNFα were found in the transplanted baboon. Furthermore, high levels of tPA-PAI-1 complexes were found, suggesting a complete loss of the pro-fibrinolytic properties of the endothelial cells. These data show that PCMV has an important impact on transplant survival and call for elimination of PCMV from donor pigs.

Performance and Development of a Miniature Rotary Shaft Pump

2005 ◽  
Vol 127 (4) ◽  
pp. 752-760 ◽  
Author(s):  
Danny Blanchard ◽  
Phil Ligrani ◽  
Bruce Gale
Keyword(s):  
Flow Rate ◽  
Pressure Rise ◽  
Electronics Cooling ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Working Fluid ◽  
Hydraulic Efficiency ◽  
Potential Applications ◽  
Total Analysis ◽  
And Performance

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a 1.168 mm hole in one end of a 2.38 mm dia shaft and cutting slots in the side of the shaft at the bottom of the bored hole such that the metal between the slots defines the impeller blades. The impeller blades and slots are 0.38 mm tall. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, hydraulic efficiency, slip factor, and flow rate, are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml∕min and 2.1 kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

An Overview of Initial Operational Experience With the Closed-Loop sCO2 Test Facility at Cranfield University

2019 ◽  
Author(s):  
Eduardo Anselmi ◽  
Ian Bunce ◽  
Vassilios Pachidis
Keyword(s):  
Closed Loop ◽  
Lessons Learned ◽  
Test Facility ◽  
Working Fluid ◽  
Operational Experience ◽  
And Performance ◽  
The Uk ◽  
And Control ◽  
Measurement And Control ◽  
Initial Objective

Abstract An experimental facility is currently operating at Cranfield University in the UK and it is being used to explore supercritical carbon dioxide as a working fluid for future bottoming power cycle applications. The initial objective of this experimental programme is to de-risk and demonstrate the robustness of a closed-loop system, whilst proving the function and performance of individual components and various measurement and control modules. This paper describes the first operational experience gained whilst operating the test facility. More specifically, it summarizes the lessons learned from the commissioning phase and first test campaigns carried out in 2018.

scholarly journals Team Incentives and Performance: Evidence from a Retail Chain

2017 ◽  
Vol 107 (8) ◽  
pp. 2168-2203 ◽  
Author(s):  
Guido Friebel ◽  
Matthias Heinz ◽  
Miriam Krueger ◽  
Nikolay Zubanov
Keyword(s):  
Field Experiment ◽  
Treatment Effect ◽  
Peer Pressure ◽  
Long Term Stability ◽  
Retail Chain ◽  
Sales Teams ◽  
And Performance ◽  
And Control ◽  
Number Of Customers

In a field experiment with a retail chain (1,300 employees, 193 shops), randomly selected sales teams received a bonus. The bonus increases both sales and number of customers dealt with by 3 percent. Each dollar spent on the bonus generates $3.80 in sales, and $2.10 in profit. Wages increase by 2.2 percent while inequality rises only moderately. The analysis suggests effort complementarities to be important, and the effectiveness of peer pressure in overcoming free-riding to be limited. After rolling out the bonus scheme, the performance of the treatment and control shops converges, suggesting long-term stability of the treatment effect. (JEL D22, J31, J33, L25, L81, M53, M54)

Design of Pneumatic and Control System for Quartz Crystal Tin Dipping Machine

2014 ◽  
Vol 527 ◽  
pp. 248-251
Author(s):  
Hong Jie Chang ◽  
Yi Ping Yang ◽  
Yan Fang Yue ◽  
Guang Yang
Keyword(s):  
Control System ◽  
Failure Rate ◽  
Quartz Crystal ◽  
Touch Screen ◽  
Pneumatic System ◽  
Stable Operation ◽  
And Control

This paper introduces the craft process and work principle of the quartz crystal tin dipping machine, and pays attention to elaborate the design content of pneumatic system and control system. The equipments control cores are Siemens small size PLC and industrial touch screen, and selects air cylinder and micro motor as the main executive components, which can guarantee the facilities reliability and flexibility, have strong anti-interference capability. Through long-term spot application, it indicates this tin dipping machine has stable operation, low failure rate and flexible and convenient operation.

scholarly journals Impact of porcine cytomegalovirus on long-term orthotopic cardiac xenotransplant survival

2020 ◽  
Author(s):  
Joachim Denner ◽  
Matthias Längin ◽  
Bruno Reichart ◽  
Luise Krüger ◽  
Uwe Fiebig ◽  
...  
Keyword(s):  
Immunosuppressive Regimen ◽  
Complete Loss ◽  
Orthotopic Heart Transplantation ◽  
Survival Times ◽  
Post Transplantation ◽  
Porcine Cytomegalovirus ◽  
And Control ◽  
First Time ◽  
Pai 1

Xenotransplantation using pig organs has achieved survival times of more than 195 days in pig orthotopic heart transplantation into baboons. Here we demonstrate that in addition to an improved immunosuppressive regimen, non-ischaemic preservation with continuous perfusion and control of post-transplantation growth of the transplant, prevention of transmission of the porcine cytomegalovirus (PCMV) plays an important role in achieving long survival times. For the first time we demonstrate that PCMV transmission in orthotopic pig heart xenotransplantation was associated with a reduced survival time of the transplant and increased levels of IL-6 and TNFα were found in the transplanted baboon. Furthermore, high levels of tPA-PAI-1 complexes were found, suggesting a complete loss of the pro-fibrinolytic properties of the endothelial cells. These data show that PCMV has an important impact on transplant survival and call for elimination of PCMV from donor pigs.

Parametric Control of a Two-Phase Thermal Management System for Space Applications

2008 ◽  
Author(s):  
M. J. Brooks ◽  
L. C. Nortje ◽  
W. E. Lear ◽  
S. A. Sherif
Keyword(s):  
Time Pressure ◽  
Waste Heat ◽  
Thermal Control ◽  
Pulse Frequency ◽  
Working Fluid ◽  
Absolute Pressure ◽  
Stable Operation ◽  
Two Phase ◽  
Space Applications ◽  
R 134A

As spacecraft increase in complexity, greater power is required to drive their onboard systems. The resulting generation of waste heat demands efficient thermal control, especially for electrical components emitting heat at high flux densities. Weislogel proposed a passive two-phase heat transport system for space application, driven by constant volume boilers, called the pulse thermal loop (PTL). This paper describes four methods of operating a PTL using real-time pressure data as the control parameter. Preliminary results are presented from an experimental loop using R-134a as the working fluid. Control is exercised through algorithm-based schemes implemented in LabVIEW. Results suggest that stable operation of the loop is best achieved by actuating flow control valves in response to a preset pressure difference between the boilers. Control schemes based on absolute pressure, set pulse frequency, and a combination of absolute and differential pressures are also described. Performance data are presented, and some of the challenges faced during PTL operation are discussed, including start-up and asymmetrical pressurization of the boilers.

Performance and Development of a Miniature Rotary Shaft Pump (RSP)

2004 ◽  
Author(s):  
Daniel B. Blanchard ◽  
Phillip M. Ligrani ◽  
Bruce K. Gale
Keyword(s):  
Flow Rate ◽  
Pressure Rise ◽  
Electronics Cooling ◽  
Maximum Flow ◽  
Operating Conditions ◽  
Working Fluid ◽  
Pump Performance ◽  
Potential Applications ◽  
Total Analysis ◽  
And Performance

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a hole in one end of a shaft, and cutting slots in the side of the shaft at the bottom of the bored hole, such that the metal between the slots defines the impeller blades. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, efficiency, slip factor, and flow rate are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml/min, and 2.1kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

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