Amuse your friends, amaze your enemies, and perplex ants and other insects, insofar as they are capable of perplexment. Accomplish all this and more with this handy dandy homebrew acoustic levitator.
Before anyone gets to thinking about using this technique to build a hoverboard that actually hovers, it’s best that you scale your expectations way, way down. Still, being able to float drops of liquid and small life forms is no mean feat, and looks like a ton of fun to boot. [Asier Marzo]’s Instructable’s post fulfills a promise he made when he first published results for what the popular press then breathlessly dubbed a “tractor beam,” which we covered back in January. This levitator clearly has roots in the earlier work, what with 3D-printed hemispherical sections bristling with ultrasonic transducers all wired in phase. A second section was added to create standing acoustic waves in the middle of the space, and as the video below shows, just about anything light enough and as least as cooperative as an ant can be manipulated in the Z-axis.
There’s plenty of room to expand on [Asier]’s design, and probably more practical applications than annoying bugs. Surface-mount devices are pretty tiny — perhaps an acoustic pick and place is possible?
Continue reading “Floating Ants and Drops of Liquid with an Acoustic Levitator”
There are innumerable password hacking methods but recent advances in acoustic and accelerometer sensing have opened up the door to side-channel attacks, where passwords or other sensitive data can be extracted from the acoustic properties of the electronics and human interface to the device. A recent and dramatic example includes the hacking of RSA encryption simply by listening to the frequencies of sound a processor puts out when crunching the numbers.
Now there is a new long-distance hack on the scene. The Cerebrum system represents a recent innovation in side-channel password attacks leveraging acoustic signatures of mobile and other electronic devices to extract password data at stand-off distances.
Continue reading “Cerebrum: Mobile Passwords Lifted Acoustically with NASB”
Don’t blame us for the click-baity titles in the source articles about this handheld “acoustic tractor beam”. You can see why the popular press tarted this one up a bit, even at the risk of drawing the ire of Star Trek fans everywhere. Even the journal article describing this build slipped the “tractor beam” moniker into their title. No space vessel in distress will be towed by [Asier Marzo]’s tractor beam, unless the aliens are fruit flies piloting nearly weightless expanded polystyrene beads around the galaxy.
That doesn’t detract from the coolness of the build, revealed in the video below. There’s no tutorial per se, but an Instructables post is promised. Still, a reasonably skilled hacker will be able to replicate the results with ease straight from the video. Using mostly off the shelf hardware, [Marzo] creates a bowl-shaped phased array of ultrasonic transducers driven by an Arduino through a DC-DC converter and dual H-bridge driver board to boost the 40 kHz square waves from 5 Vpp to 70 Vpp. By controlling the phasing of the signals, the tractor beam can not only levitate small targets but also move them axially. It looks like a lot of fun.
Acoustic levitation is nothing new here – we’ve covered 3D acoustic airbending, as well as an acoustic flip-dot display. Being able to control the power of sound waves in a handheld unit is a step beyond, though.
Continue reading “Acoustic Levitation with a Twist”
Brothers [Armand] and [Victor] took their acoustic guitar to the next level, making their own pickups to turn it into an electric guitar. The result is that awesome electric guitar sound.
The pickups are homemade magnetic pickups. Each string has a steel bolt behind it with three ceramic magnets on each bolt. A coil is also wrapped around all the pickups. That coil is what’s connected to the wires going to the amplifier. When a string vibrates, it changes the magnetic field in the pickup which induces a current in the coil and that is then sent on to the amplifier to be altered as desired and turned back into sound. Of course that meant the guys had to replace their nylon strings for steel ones.
With just the volume amplified the sound isn’t very different but when the amplifier’s gain is turned up and the volume turned down the sound is undoubtedly electric. As you can hear in the video below, Johnny B. Goode, Paint it Black and Satisfaction take their acoustic guitar’s sound to a whole new level.
Continue reading “Rocking An Acoustic Guitar By Making It Electric”
We all know that guy (or, in some cases, we are that guy) that can listen to a car running and say something like, “Yep. Needs a lifter adjustment.” A startup company named Augury aims to replace that skill with an iPhone app.
Aimed at commercial installations, a technician places a magnetic sensor to the body of the machine in question. The sensor connects to a custom box called an Auguscope that collects vibration and ultrasonic data and forwards it via the iPhone to a back end server for analysis. Moving the sensor can even allow the back end to determine the location of the fault in some cases. The comparison data the back end uses includes reference data on similar machines as well as historical data about the machine in question.
Continue reading “Listen Up: iPhone Hack Diagnoses HVAC”
Normally you’d expect the sound of a pipe organ to come from something gigantic. [Matthew Steinke] managed to squeeze all of that rich melodic depth into an acoustic device the size of a toaster (YouTube link) which uses electromagnetism to create its familiar sound.
[Matthew ’s] instrument has a series of thin vertical tines, each coupled with a small MIDI controlled electromagnet. As the magnet pulses with modulation at a specific frequency, the pull and release of the tine causes it to resonate continuously with a particular tone. The Tine Organ is capable of producing 20 chromatic notes in full polyphony starting in middle C and can be used as an attachment to a standard keyboard or a synthesizer app on a smart phone. The classic style body of the instrument is made out of mahogany and babinga and houses the soundboard as well as the mini microcontroller responsible for receiving the MIDI and regulating the software oscillators sending voltage to the magnets.
[Matthew’s] creation is as interesting to look at as it is to listen to, so I’d recommend checking out the video below to hear the awesome sound it produces:
Continue reading “Using MIDI and Magnets to Produce Tones with Tines”
It’s easy to dismiss this one at first glance. But once you hear [Tychsen81] playing the thing you’ll want to know more.
He posted the demonstration way back in 2009. It wasn’t until a year later that he filmed the particulars of how the thing was made. The strings are actually bass guitar strings, an A and D string that are tuned down to E and A to play along with Black Sabbath’s “Ironman”. The neck is made out of two boards. One serves as the fingerboard, which is fretless. The other is mounted under that in order to provide negative space for the bridge while keeping the strings at the right height for the fingerboard. The water bottle helps to amplify the sound and that’s why the bottom end of the strings pivot on the bridge, pass through the neck, and are anchored on the bottom edge of the bottle.
We’ve embedded both the demo and the build videos after the break.
If this gets you thinking about making your own instruments you will also be interested in the Whamola.
Continue reading “Acoustic bass guitar uses water jug and two strings”