Mothbox Watches Bugs, So You — Or Your Grad Students — Don’t Have To

September 19, 2024 by Dan Maloney 8 Comments

To the extent that one has strong feelings about insects, they tend toward the extremes of a spectrum that runs from a complete fascination with their diversity and the specializations they’ve evolved to exploit unique and ultra-narrow ecological niches, and “Eww, ick! Kill it!” It’s pretty clear that [Dr. Andy Quitmeyer] and his team tend toward the former, and while they love their bugs, spending all night watching them is a tough enough gig that they came up with Mothbox, the automated insect monitor.

Insect censuses are valuable tools for assessing the state of an ecosystem, especially insects’ vast numbers, short lifespan, and proximity to the base of the food chain. Mothbox is designed to be deployed in insect-rich environments and automatically recognize and tally the moths it sees. It uses an Arducam and Raspberry Pi for image capture, plus an array of UV and visible LEDs, all in a weatherproof enclosure. The moths are attracted to the light and fly between the camera and a plain white background, where an image is captured. YOLO v8 locates all the moths in the image, crops them out, and sends them to BioCLIP, a vision model for organismal biology that appears similar to something we’ve seen before. The model automatically sorts the moths by taxonomic features and keeps a running tally of which species it sees.

Mothbox is open source and the site has a ton of build information if you’re keen to start bug hunting, plus plenty of pictures of actual deployments, which should serve as nightmare fuel to the insectophobes out there.

Trees Turned Into Wind Turbines, Non-Destructively

September 18, 2024 by Bryan Cockfield 57 Comments

Trees and forests are an incredibly important natural resource — not only for lumber and agricultural products, but also because they maintain a huge amount of biodiversity, stabilize their local environments, and help combat climate change as a way to sequester atmospheric carbon. But the one thing they don’t do is make electricity. At least, not directly. [Concept Crafted Creations] is working on solving this issue by essentially turning an unmodified tree into a kind of wind turbine.

The idea works by first attaching a linear generator to the trunk of a tree. This generator has a hand-wound set of coils on the outside, with permanent magnets on a shaft that can travel up and down inside the set of coils. The motion to power the generator comes from a set of ropes connected high up in the tree’s branches. When the wind moves the branches, the ropes transfer the energy to a 3D printed rotational mechanism attached to a gearbox, which then pumps the generator up and down. The more ropes, branches, and generators attached to a tree the more electricity can be produced.

Admittedly, this project is still a proof-of-concept, although the currently deployed prototype seems promising. [Concept Crafted Creations] hopes to work with others building similar devices to improve on the idea and build more refined prototypes in the future. It’s also not the only way of building a wind energy generator outside of the traditional bladed design, either. It’s possible to build a wind-powered generator with no moving parts that uses vibrations instead of rotational motion as well.

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Mowing The Lawn With Lasers, For Science

September 3, 2024 by Maya Posch 34 Comments

Cutting grass with lasers works great in a test setup. (Credit: Allen Pan, YouTube)

Wouldn’t it be cool if you could cut the grass with lasers? Everyone knows that lasers are basically magic, and if you strap a diode laser or two to a lawn mower, it should slice through those pesky blades of grass with zero effort. Cue [Allen Pan]’s video on doing exactly this, demonstrating in the process that we do in fact live in a physics-based universe, and lasers are not magical light sabers that will just slice and dice without effort.

The first attempt to attach two diode lasers in a spinning configuration like the cutting blades on a traditional lawn mower led to the obvious focusing issues (fixed by removing the focusing lenses) and short contact time. Effectively, while these diode lasers can cut blades of grass, you need to give them some time to do the work. Naturally, this meant adding more lasers in a stationary grid, like creating a Resident Evil-style cutting grid, only for grass instead of intruders.

Does this work? Sort of. Especially thick grass has a lot of moisture in it, which the lasers have to boil off before they can do the cutting. As [Allen] and co-conspirator found out, this also risks igniting a lawn fire in especially thick grass. The best attempt to cut the lawn with lasers appears to have been made two years ago by [rctestflight], who used a stationary, 40 watt diode laser sweeping across an area. When placed on a (slowly) moving platform this could cut the lawn in a matter of days, whereas low-tech rapidly spinning blades would need at least a couple of minutes.

Obviously the answer is to toss out those weak diode lasers and get started with kW-level chemical lasers. We’re definitely looking forward to seeing those attempts, and the safety methods required to not turn it into a laser safety PSA.

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3D Printed Homes Are All The Hype, But What Is Their Real Impact?

September 1, 2024 by Maya Posch 67 Comments

Additive manufacturing (AM) has been getting a lot of attention over the years, with its use in construction a recurring theme. Generally this brings to mind massive 3D printers that are carted to construction sites and assemble entire homes on the spot. That’s the perspective with which a recent ZDNet article by [Rajiv Rao] opens, before asking whether AM in construction is actually solving any problems. As [Rajiv] notes, the main use of such on-site AM construction is for exclusive, expensive designs, such as ICON’s House Zero which leans into the extruded concrete printing method.

Their more reasonable Wolf Ranch residential homes in Texas also use ICON’s Vulcan II printer to print walls out of concrete, with a roof, electrical wiring, plumbing, etc. installed afterwards. Prices for these Wolf Ranch 3 to 4 bedroom houses range from about $450,000 to $600,000, and ICON has been contracted by NASA to work a way to 3D print structures on the Moon out of regolith.

Naturally, none of these prices are even remotely in the range of the first-home buyers, or the many economically disadvantaged who make up a sizable part of the population in the US and many other nations in the Americas, Africa, etc. To make AM in construction economically viable, it would seem that going more flatpack and on-site assembly is the way to go, using the age-old pre-fabrication (prefab) method of constructions.

This is the concept behind the University of Maine’s BioHome3D, which mainly uses PLA, wood fiber and similar materials to create modules that contain insulation in the form of wood fiber and cellulose. These modules are 3D printed in a factory, after which they’re carted off to the construction site for assembly, pretty much like any traditional prefab home, just with the AM step and use of PLA rather than traditional methods.

Prefab is a great way to speed up construction and already commonly used in the industry, as modules can have windows, doors, insulation, electrical wiring, plumbing, etc. all installed in the factory, with on-site work limited to just final assembly and connecting the loose bits. The main question thus seems to be whether AM in prefab provides a significant benefit, such as in less material wasted by working from (discarded) wood pulp and kin.

While in the article [Rajiv] keeps gravitating towards the need to use less concrete (because of the climate) and make homes more affordable through 3D printing, AM is not necessarily the panacea some make it out to be, due to the fact that houses are complex structures that have to do much more than provide a floor, walls and a roof. If adding a floor (or two) on top of the ground floor, additional requirements come into play, before even considering aspects like repairability which is rarely considered in the context of AM construction.

Swiss Researchers May Have Solved Hydrogen Storage

September 1, 2024 by Jenny List 102 Comments

If you follow the world of clean energy, you will probably have read all about the so-called hydrogen future and the hydrogen economy. The gas can easily be made from water by electrolysis from green solar electricity, contains a lot of stored energy which is clean to recover, and seems like the solution to many of our green energy woes. Sadly the reality doesn’t quite match up as hydrogen is difficult to store and transport, so thus far our hydrogen cars haven’t quite arrived. That hasn’t stopped researchers looking at hydrogen solutions though, and a team from ETH Zurich might just have found a solution to storing hydrogen. They’re using it to reduce iron oxide to iron, which can easily release the hydrogen by oxidation with water.

Their reactor is simplicity itself, a large stainless steel tank filled with powdered iron ore. Pump hydrogen into it and the iron oxide in the ore becomes water and iron which forms the storage medium, and retrieve the hydrogen later by piping steam through the mixture. Hydrogen generated in the summer using solar power can then be released in the winter months. Of course it’s not perfectly efficient, and a significant quantity of energy is lost in heat, but if the heat is recovered and used elsewhere that effect can be mitigated. The hope is that their university might be benefiting from a pilot plant in the coming years, and then perhaps elsewhere those hydrogen grids and cars might become a reality. We can hope.

Meanwhile, in the past we’ve looked at a not quite so green plan for a hydrogen grid.

An L-shaped orange mounting structure with two white reservoirs on top, a set of pumps on the outer bottom edges, and a membrane cell bolted together in the center. The parts are connected by a series of transparent tubes.

Open Source Residential Energy Storage

August 15, 2024 by Navarre Bartz 20 Comments

Battery news typically covers the latest, greatest laboratory or industry breakthroughs to push modern devices further and faster. Could you build your own flow battery stationary storage for home-built solar and wind rigs though?

Based on the concept of appropriate technology, the system from the Flow Battery Research Collective will be easy to construct, easy to maintain, and safe to operate in a residential environment. Current experiments are focusing on Zn/I chemistry, but other aqueous chemistries could be used in the future. Instead of an ion exchange membrane, the battery uses readily attainable photo paper and is already showing similar order of magnitude performance to lab-developed cells.

Any components that aren’t off-the-shelf have been designed in FreeCAD. While they can be 3D printed, the researchers have found traditional milling yields better results which isn’t too surprising when you need something water-tight. More work is needed, but it is promising work toward a practical, DIY-able energy storage solution.

If you’re looking to build your own open source wind turbine or solar cells to charge up a home battery system, then we’ve got you covered. You can also break the chains of the power grid with off-the-shelf parts.

Australia’s Controlled Loads Are In Hot Water

August 15, 2024 by Lewin Day 125 Comments

Australian grids have long run a two-tiered pricing scheme for electricity. In many jurisdictions, regular electricity was charged at a certain rate. Meanwhile, you could get cheaper electricity for certain applications if your home was set up with a “controlled load.” Typically, this involved high energy equipment like pool heaters or hot water heaters.

This scheme has long allowed Australians to save money while keeping their water piping-hot at the same time. However, the electrical grid has changed significantly in the last decade. These controlled loads are starting to look increasingly out of step with what the grid and the consumer needs. What is to be done?