American Science And Surplus Ends Online Sales

September 17, 2025 by 29 Comments

For nearly 90 years, American Science and Surplus has been shipping out weird and wonderful stuff to customers far and wide. In the pre-Internet days, getting their latest catalog in the mail — notable for its hand-drawn illustrations and whimsical style — was always exciting. From Romanian gas masks to odd-ball components, there was no telling what new wonders each issue would bring. In time, the printed catalog gave way to a website, but the eclectic offerings and hand-drawn images remained.

Unfortunately, those days are officially no more. Earlier this week, American Science and Surplus had to make the difficult decision to shutter their entire mail order division. It’s no secret that the company as a whole had been struggling over the last few years. Like many small businesses they were hit hard during the COVID-19 years, and while they made it through that particular storm, they faced skyrocketing operational costs.

Earlier this year, the company turned to crowd funding to help stay afloat. That they were able to raise almost $200,000 speaks to how much support they had from their community of customers, but while it put the company in a better position, the writing was on the wall. The warehouse space required to support their mail order operations was simply too expensive to remain viable.

But it’s not all bad news. At least two of the company’s physical storefronts, located in Milwaukee, Wisconsin and Geneva, Illinois will remain open and operate under the ownership of the employees themselves. The fate of the third store in Park Ridge, Illinois is less clear. They currently don’t have a buyer, but it sounds like they haven’t given up hope of selling it yet.

Anyone in the Illinois area feel like getting some buddies together and buying a turn-key surplus business?

A Simple Science Fair AM Transmitter

January 23, 2020 by 18 Comments

A crystal radio is a common enough science fair project, but the problem is, there isn’t much on anymore. The answer is, of course, obvious: build your own AM transmitter, too. AM modulation isn’t that hard to do and [Science Buddies] has plans for how to build one with a canned oscillator and an audio transformer.

We don’t imagine the quality of this would be so good, but for a kid’s science project it might be worth a shot. Maybe something like “What kind of materials block radio waves?” would be a good project statement.

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Build A Light Following Bristlebot As A Way To Teach Science

June 29, 2013 by 13 Comments

light-following-bristlebot

[Ben Finio] designed this project as a way to get kids interested in learning about science and engineering. Is it bad that we just want to build one of our own? It’s a light following bristlebot which in itself is quite simple to build and understand. We think the platform has a lot of potential for leading to other things, like learning about microcontrollers and wireless modules to give it wireless control.

Right now it’s basically two bristlebots combined into one package. The screen capture seen above makes it hard to pick out the two toothbrush heads on either side of a battery pack. The chassis of the build is a blue mini-breadboard. The circuit that makes it follow light is the definition of simple. [Ben] uses two MOSFETs to control two vibration motors mounted on the rear corners of the chassis. The gate of each MOSFET is driven by a voltage divider which includes a photoresistor. When light on one is brighter than the other it causes the bot to turn towards to the brighter sensor. When viewing the project log above make sure to click on the tabs to see all of the available info.

This directional control seems quite good. We’ve also seen other versions which shift the weight of the bot to change direction.

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Diffuse glow of red, green, and blue LEDs embedded in silicone

Embedded LEDs For Soft Robots Made From Silicone

July 23, 2025 by 3 Comments

Over on their YouTube channel [Science Buddies] shows us how to embed LEDs in soft robots. Soft robots can be made entirely or partially from silicone. In the video you see an example of a claw-like gripper made entirely from silicone. You can also use silicone to make “skin”. The skin can stretch, and the degree of stretch can be measured by means of an embedded sensor made from stretchy conductive fabric.

As silicone is translucent if you embed LEDs within it when illuminated they will emit diffuse light. Stranded wire is best for flexibility and the video demonstrates how to loop the wires back and forth into a spring-like shape for expansion and contraction along the axis which will stretch. Or you can wire in the LEDs without bending the wires if you run them along an axis which won’t stretch.

The video shows how to make silicone skin by layering two-part mixture into a mold. A base layer of silicone is followed by a strip of conductive fabric and the LED with its wires. Then another layer of silicone is applied to completely cover and seal the fabric and LED in place. Tape is used to hold the fabric and LED in place while the final layer of silicone is applied.

When the LEDs are embedded in silicone there will be reduced airflow to facilitate cooling so be sure to use a large series resistor to limit the current through the LED as much as possible to prevent overheating. A 1K series resistor would be a good value to try first. If you need the LED to be brighter you will need to decrease the resistance, but make sure you’re not generating too much heat when you do so.

If you’re interested in stretchy circuits you might also like to read about flexible circuits built on polyimide film.

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Custom Dog Door Prevents Culinary Atrocities

April 17, 2024 by 32 Comments

Riley, an 8 lb pug, has more beauty than brains, and a palate as unrefined as crude oil. While we hate criticizing others’ interests and tastes, his penchant for eating cat poop needed to stop. After a thorough exploration of a variety of options, including cat food additives that make its excrement taste worse (HOW? WHY? Clearly taste wasn’t the issue!), automatic litter boxes that stow the secretions, and pet doors that authenticate access to the room with the litter box, [Science Buddies] eventually settled on a solution that was amenable to all members of the family.

The trick was in creating a door mechanism with a blacklist of sorts rather than a whitelist. As the cat didn’t like to push the door open itself, the solution needed to have the pet door open by default. A magnet on Riley’s collar would trip a sensor attached to an Arduino that would control servos to swing the door shut immediately if he attempted to access the defecated delights. Of course safety was a consideration with the door swinging in Riley’s face.

We’ve covered a few pet screeners, including one for the same purpose that used IR sensors (but a much bigger dog also named Riley), and a flock of solutions for chickens. We’ve also seen [Science Buddies] in previous posts, so they’re not on the tips line blacklist.

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Water Drips Up In Kid-Friendly Engineering Experiment

July 11, 2022 by 7 Comments

Did you know that water can drip UP instead of down? It’s true! Okay, okay- it’s a bit of an optical illusion, but one that’s mesmerizing no less, and it’s one that is especially awe-inspiring for kids. As [Science Buddies] explains in the video below the break, it’s also achievable for anyone with some basic supplies.

On first glance, the “water dripping upward” illusion looks like it must be extremely complicated with precisely timed drops, and perfectly triggered strobing lights and the like- right? Well, not so much. [Science Buddies] demonstrates a highly simplified experiment using only an aquarium pump, a basic frame, a smart phone with a strobing app, and naturally, water. The experiment is presented in a simple manner that would allow a young person to replicate it without too much adult intervention.

The video goes into such concepts as frequency, duty cycle (pulse width modulation), and other basic engineering principles. The experiment can be completed for just a few dollars for the pump and tubing, and the rest can be improvised. What a great way to get a young one started on their way to engineering!

If you’d like to see a more fleshed out version of a similar machine, check out this gravity defying dripper we featured a few years ago.
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Learn Multirotors From First Principles

April 11, 2021 by 5 Comments

Multirotors, or drones as they’re popularly called, are so ubiquitous as to have become a $10 toy. They’re no less fun to fly for it though, and learning how they work is no less fascinating. It’s something [Science Buddies] has addressed in a series of videos examining them from first principles. They may be aimed at youngsters, but they’re still an entertaining enough watch for those of advancing years.

Instead of starting with a multirotor control board, the video takes four little DC motors and two popsicle sticks to make a rudimentary drone frame. Then with the help of dowels and springs it tethers the craft as the control mechanisms are explained bit by bit, from simple on-off motor control through proportional control to adding an Arduino and following through to how a multirotor stays in flight. It’s instructional and fun to watch, and maybe even for some of us, a chance to learn something.

We’ve had multirotor projects aplenty here over the years, but how about something completely different made from popsicle sticks?

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