Part 1 of our Wind Load Series “Wind load” is a calculated value representing the total force on a structure or object cause by pressure from wind moving over it. In this blog series, we will discuss different methods for wind load calculations, the factors that influence its magnitude, and the effects a high wind load can have on a structure. Wind load is most commonly addressed by civil and structural engineers when designing buildings, but mechanical engineers can encounter the effect when designing tall objects like cranes, telescoping communications masts or wind turbine towers. Wind Load Essentials As a force, wind load is the product of pressure distributed over an area (psf times ft2 or Pa times m2). In [...]
Figure 1: Unpowered Sony Ericsson S500i LCD screen at 200x magnification In our last blog post, I wrote about some of the physics and materials science principles that go into the design and manufacture of liquid-crystal display (LCD) screens. The eponymous liquid crystals (LCs) in such a display have to be quite small in order to create a seamless image; as I mentioned in the last entry, the subpixels (the red, green and blue elements comprising a pixel, visible in Figure 1) can be smaller than a red blood cell. Each of these subpixels needs its own control system that interacts with the data drivers along the periphery of the screen. These power and control circuit components [...]
Figure 1: Composite layered heater from patent US 9,224,626 B2 Alexander Glew, Ph.D., P.E. recently contributed to a new patent on an advanced thin-film electric heaters, layered composite heaters, for CVD semiconductor processing and related technologies titled “Composite substrate for layered heaters”. Watlow Electric, based in St. Louis, hired Glew Engineering and Dr. Glew to help develop this heater technology due to his experience in the Silicon Valley’s semiconductor industry. As a semiconductor equipment expert and materials engineering consultant, Dr. Glew’s familiarity with semiconductor manufacturing meant he understood both the limitations of common semiconductor chuck heating methods and the techniques that could be used to construct a better heater. In this post, we review how this composite heater capitalizes on semiconductor [...]
Figure 1: Simplified model of an aluminum-glass window In last week’s blog, Thermal Expansion in a Glass and Aluminum Window: Part 1, we introduced the basic concept of thermal expansion in solid materials. Since CTE mismatch can impose extremely high stress, during mechanical engineering design one must consider the temperature exposure and expansion or contraction of a material. In order to help the read gain insight, we used a simplified aluminum-framed window to demonstrate that a hot summer day would be enough to shatter glass if the window wasn’t equipped with a flexible gasket between the frame and the glass. For this entry, we utilize a finite element analysis (FEA) to elucidate the stress effects caused by both high and [...]
Equipment designers must accommodate thermal expansion (CTE)of dissimilar materials, especially when they are subject to large temperature changes. This problem is often called "CTE mismatch." In this blog, we give the fundamentals of thermal expansion calculations used in thermo-mechanical analysis. These calculations are simple but useful, and easy enough to perform by hand or with a spread sheet. For more complicated shapes, one must use computer modeling. As an example, we perform a finite element analysis (FEA) in a later blog http://glewengineering.com/thermal-expansion-in-a-glass-and-aluminum-window-part-2/, of a glass and aluminum window and frame to show where the stress is excessive. This points to the obvious need for a gasket to perform as a thermal interface material, in order to lessen [...]
Portrait of Galileo Galilei Justus Sustermans [Public domain], via Wikimedia Commons I’d like to return to our previous series on the Italian Masters, focused not on the usual masters or painting and sculpture but on the masters or science, mathematics, and engineering. So far in the series I’ve written about the accomplishments of Volta, Cassini, Venturi and Torricelli. Today, I’d like to look at one of the greats: Galileo Galilei. Galileo is most famous today for standing up for heliocentrism against the Catholic Church and spending the last years of his life under house arrest as punishment. However, Galileo didn’t let controversies or confinement stop him, and accomplished a great amount of research in not only [...]
Figure 1: Allesandro Volta We’ve been taking a break from hard-hitting mechanical engineering and materials science blogs with some pieces on the Italian masters of science, mathematics and engineering in the 16-19th centuries. I’ve previously explored the lives and contributions of Evangelista Torricelli, Giovanni Venturi and Giovanni Cassini. For this blog, I’m focusing on Alessandro Volta, who helped revolutionize our understanding of electricity and electrochemstry it in the late 18th century. […]
Figure 1: Mars Exploration Rover mobility testing By NASA
Figure 1: Diagram of the scientific equipment on MER-B Opportunity Mars Exploration Rover Launches Press Kit, June 2003, p. 41 [i] I mentioned in a blog last week that Mars Exploration Rover B (FIgure 1), more affectionately called Opportunity, recently celebrated the 12th anniversary (in Earth years) of its landing on Mars. 12 years without maintenance on the hostile surface of another planet is incredible, considering the original operational time was planned for only 3 months. Mars Science Laboratory Curiosity currently gets the most press, with its larger tool library and fancier cameras, but there are still scientists and engineers at JPL piloting Opportunity from one scientific site to the next. In the last blog, I mentioned [...]
12 Years a Martian: Engineering Challenges on the Red Planet GalleryCAD, Electrical Engineering, Engineering Consulting, Expert Witness, Licensed Mechanical Engineer, Materials Science, Mechanical Engineering, Mechanical Engineering Consulting, Solar Car, Solar Cars, Solar Vehicle, Thermal Management
Figure 1: Mars Exploration Rover By NASA/JPL/Cornell University, Maas Digital LLC [Public domain], via Wikimedia Commons Depending on which Facebook pages or Twitter feeds you follow, some of you may have caught wind that Opportunity (Mars Exploration Rover B, Figure 1) recently passed its twelfth anniversary of its landing on the red planet. Opportunity’s ongoing trek across Mars represents a fantastic accomplishment in engineering. At the time I’m writing this, the rover has been in continual operation for over 4,300 Earth days (that’s about 4,185 Sols, or Martian days). Considering its original planned mission time of 92 Earth days, Opportunity has exceeded its design lifetime by 4,700%. Imagine having a car that, instead of a [...]
A close look at how 2-D phosphorus is being used in 2-Dimensional drumhead resonators, and what this means for future electronic devices.
Mechanical engineers at MIT created a new material made from polyurethane foam and wax, which may find application for "soft" robots.
Materials Science News: 2-D Phosphorus-The Future for Solar Cells? GalleryElectrical Engineering, Energy Efficiency, Engineering Consulting, Material Engineer, Materials Science, Mechanical Engineering, Mechanical Engineers, Templates
Materials science research shows that 2-dimensional phosphorus could be the future for the semiconductor industry.
Standford School of Engineering researchers are studying ways to make more efficient fuel cells.
Thin-film transistors and field emission transistors made from 2-D materials could lead to a new class of electronic devices.
Magnesium chloride can replace cadmium chloride in the thin film solar cell process.
UC Riverside engineering team uses silicon dioxide found in Silly Putty to improve lithium-ion batteries.
Semiconductor Industry Uses Colorful Diamonds to Measure Magnetic Fields in Semiconductors
A basic review of chemical vapor deposition and how it is used in semiconductor processing.
A brief review of ion implantation in the semiconductor processing industry.