Floating Solar Farms Are Taking The World’s Reservoirs By Storm

January 24, 2022 by Lewin Day 60 Comments

Photovoltaic solar panels are wonderful things, capable of capturing mere light and turning it into useful electricity. They’re often installed on residential and commercial rooftops for offsetting energy use at the source.

However, for grid-scale generation, they’re usually deployed in huge farms on tracts of land in areas that receive plenty of direct sunlight. These requirements can often put solar farms in conflict with farm-farms — the sunlight that is good for solar panels is also good for growing plants, specifically those we grow for food.

One of the more interesting ideas, however, is to create solar arrays that float on water. Unlike some of the wackier ideas out there, this one comes with some genuinely interesting engineering benefits, too!

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Printing Your Own Exoskeleton

January 20, 2022 by Matthew Carlson 23 Comments

While not quite in a cave, the idea of making your own exoskeleton with limited tools does have a Tony Stark esque vibe. [Andrew Piccinno] is a mechanical engineer pursuing the dream of 3D printing a full-body exoskeleton called 3X0. It’s a project he’s been ruminating on since college, but the work really began in earnest about five months ago. Unfortunately, there are too many pictures to include here, but check out his Instagram or makeprojects for more photos.

To make sure parts fit, [Andrew] started with creating a mesh of his body. After running fifty pictures of himself holding relatively still through some photogrammetry software, he had a decent mesh. While measurements weren’t millimeter-accurate, the relative sizes of everything were reasonably accurate. While the design is modeled with his measurements in mind, all the different pieces are parametric, which in theory would allow someone to tweak the designs to fit their own body.

So far, all the parts have been entirely 3D printed, except for steel balls bearings, gas pistons, and tension bands. The non-3D printed parts are picked to be easy to obtain as the gas piston is just 100 N furniture pistons. The design process includes quite a bit of math, motion study, and simulation to make sure the part that he’s printing will not only fit but move correctly. Many parts, such as the shoulder, are built around a large custom bearing that allows the piece to move correctly with the user’s joints.

While still in the middle of development, [Andrew] has made some serious progress, and we’re looking forward to seeing it completed. The current design is primarily passive with just a few springs and pistons, but he is already looking forward to making it active to the degree that it can augment a user’s motions rather than just taking the load off. It’s clear that [Andrew] believes that exoskeletons are a look into a potential future, and we couldn’t agree more. In a similar vein, perhaps the techniques used in this powered exoskeleton arm on a budget could be used to power the 3X0?

Longer Range EVs Are On The Horizon

January 19, 2022 by Lewin Day 165 Comments

When electric cars first started hitting the mainstream just over a decade ago, most criticism focused on the limited range available and the long recharge times required. Since then, automakers have been chipping away, improving efficiency here and adding capacity there, slowly pushing the numbers up year after year.

Models are now on the market offering in excess of 400 miles between charges, but lurking on the horizon are cars with ever-greater range. The technology stands at a tipping point where a electric car will easily be able to go further on a charge than the average driver can reasonably drive in a day. Let’s explore what’s just around the corner.

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From Nanoamps To Gigahertz: The World’s Most Extreme Op Amps

January 6, 2022 by Robin Kearey 104 Comments

The operational amplifier, or op amp, is one of the most basic building blocks used in analog circuits. Ever since single-chip op amps were introduced in the 1960s, thousands of different types have been developed, some more successful than others. Ask an experienced analog designer to name a few op amps, and they’ll likely mention the LM324, the TL072, the NE5534, the LM358, and of course the granddaddy of all, the uA741.

If those part numbers don’t mean anything to you, all you need to know is that these are generic components that you can buy anywhere and that will do just fine in the most common applications. You can buy fancier op amps that improve on some spec or another, sometimes by orders of magnitude. But how far can you really push the concept of an operational amplifier? Today we’ll show you some op amps that go way beyond these typical “jellybean” components.

Before we start, let’s define what exactly we mean when we say “operational amplifier”. We’re looking for integrated op amps, meaning a single physical component, that have a differential high-impedance voltage input, a single-ended voltage output, DC coupling, and high gain meant to be used in a feedback configuration. We’re excluding anything made from discrete components, as well as less-general circuits like fixed-gain amplifiers and operational transconductance amplifiers (OTAs).

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Does This Lead Make My Car Look Fat?

January 5, 2022 by Lewin Day 64 Comments

When looking at the performance of a vehicle, weight is one of the most important factors in the equation. Heavier vehicles take more energy to accelerate and are harder to stop. They’re also more difficult to control through the corners. Overall, anything that makes a vehicle heavier typically comes with a load of drawbacks to both performance and efficiency. You want your racecar as light as possible.

However, now and then, automakers have found reason to intentionally add large weights to vehicles. We’ll look at a couple of key examples, and discuss why this strange design decision can sometimes be just what the engineers ordered.

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Quantum Atomic Interferometer For Precision Motion Sensing

December 28, 2021 by Dave Rowntree 16 Comments

The current state of the art of embedded motion sensing is based around micro-electromechanical systems (MEMS) devices. These miracles of microfabrication use tiny silicon structures, configured to detect acceleration and rotational velocity in three dimensions. Accumulate these accelerations and rotations, and you’ve got a device that can find its orientation and track movement without any external waypoints. This is the basis of the technique of dead reckoning.

Why do we care about dead reckoning anyway? Surely GPS and related positioning systems are good enough? Above ground GPS is usually good enough, but underwater and underground this simply won’t work. Even heading indoors has a dramatic effect on the GPS signal strength, so yes, we need another way for some applications.

Right now, the current state of the art in portable sensors are MEMS devices, and you can get them for the cost of a hamburger. But if you want the ultimate in accuracy, you’ll want a quantum atomic interferometer. What that is, and how it will be possible to make one small enough to be useful, is half of the story. But first, let’s talk MEMS.

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Mining And Refining: From Red Dirt To Aluminum

December 13, 2021 by Dan Maloney 29 Comments

No matter how many syllables you use to say it, aluminum is one of the most useful industrial metals we have. Lightweight, strong, easily alloyed, highly conductive, and easy to machine, cast, and extrude, aluminum has found its way into virtually every industrial process and commercial product imaginable.

Modern life would be impossible without aluminum, and yet the silver metal has been in widespread use only for about the last 100 years. There was a time not all that long ago that aluminum dinnerware was a status symbol, and it was once literally worth more than its weight in gold. The reason behind its one-time rarity lies in the effort needed to extract the abundant element from the rocks that carry it, as well as the energy to do so. The forces that locked aluminum away from human use until recently have been overcome, and the chemistry and engineering needed to do that are worth looking into in our next installment of “Mining and Refining.”

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