Sounding A Sour Note Can Save People From A Sour Stomach (Or Worse)

We’ve covered construction of novel music instruments on these pages, and we’ve covered many people tearing down scientific instruments. But today we’ve got something that managed to cross over from one world of “instrument” into another: a music instrument modified to measure a liquid’s density by listening to changes in its pitch.

This exploration started with a mbira, a mechanically simple music instrument. Its row of rigid metal tines was replaced with a single small diameter hollow metal tube. Filling the tube with different liquids would result in different sounds. Those sounds are captured by a cell phone and processed by an algorithm to calculate the difference in relative density of those liquids. Once the procedure was worked out, the concept was verified to work on a super simple instrument built out of everyday parts: a tube mounted on a piece of wood.

At this point we have something that would be a great science class demonstration, but the authors went a step further and described how this cheap sensor can be used to solve an actual problem: detecting counterfeit pharmaceuticals. Changing composition of a drug would also change its density, so a cheap way to compare densities between a questionable sample against a known good reference could be a valuable tool in parts of the world where chemistry labs are scarce.

For future development, this team invites the world to join them applying the same basic idea in other ways, making precise measurements for almost no cost. “Any physical, chemical, or biological phenomena that reproducibly alters the pitch-determining properties of a musical instrument could in principle be measured by the instrument.” We are the ideal demographic to devise new variations on this theme. Let us know what you come up with!

If you need to do quick tests before writing analysis software, audio frequency can be measured using the Google Science Journal app. We’ve seen several hacks turning a cell phone’s camera into instruments like a spectrometer or microscope, but hacks using a phone’s microphone is less common and ripe for exploration. And anyone who manages to make cool measurements while simultaneously making cool music will instantly become a serious contender in our Hackaday Prize music instrument challenge!

[via Science News]

Ancient Insect Scales Analyzed With Help Of Nose Hair

Scientists working to advance the frontier of knowledge frequently also need to invent their tools along the way. Sometimes these are interesting little hacks to get a job done. Recently some researchers found ancestors of moths and butterflies older than any previously known by analyzing tiny scales found alongside ancient pollen. They needed a tool to manipulate these scales: separating them from surrounding debris, transferring them to microscope slides. The special tool was a needle tipped with a single human nostril hair.

As ancient insects were the published paper‘s focus, their use of nose hair tipped needle was only given a brief mention in the “Materials and Methods” section. Interviews by press quoted researchers’ claim that nose hair has the right mechanical properties for the job, without further details. Not even a picture of the tool itself. What properties of insect scales made them a good match with the properties of nose hair? Was there a comprehensive evaluation of multiple types of hair for the task? Would we regret asking these questions?

Novel approaches to fine-tipped tools would be interesting to examine under other contexts, like the tweezers we use to build surface-mount electronics. As SMD parts continue to shrink in size, will we reach a point where hair-tipped tools are the best DIY alternative to an expensive pick-and-place machine? It would be another creative approach to deal with the challenges of hand-built SMD. From simple but effective mechanical helpers, to handy 3D printed tools, to building hybrid Manual + CNC pick-and-place more affordable than their fully automated counterparts.

[via Washington Post]

Optogenetics for 100 Euros

Larval zebrafish, Drosophila (fruit fly), and Caenorhabditis elegans (roundworm) have become key model organisms in modern neuroscience due to their low maintenance costs and easy sharing of genetic strains across labs. However, the purchase of a commercial solution for experiments using these organisms can be quite costly. Enter FlyPi: a low-cost and modular open-source alternative to commercially available options for optogenetic experimentation.

One of the things that larval zebrafish, fruit flies, and roundworms have in common is that scientists can monitor them individually or in groups in a behavioural arena while controlling the activity of select neurons using optogenetic (light-based) or thermogenetic (heat-based) tools.

FlyPi is based on a 3D-printed mainframe, a Raspberry Pi computer, and a high-definition camera system supplemented by Arduino-based optical and thermal control circuits. FlyPi features optional modules for LED-based fluorescence microscopy and optogenetic stimulation as well as a Peltier-based temperature simulator for thermogenetics. The complete version with all modules costs approximately €200 with a layman’s purchasing habits, but for those of us who live on the dark side of eBay or the depths of Taobao, it shouldn’t cost more than €100.

Once assembled, all of the functions of FlyPi can be controlled through a graphical user interface. As an example for how FlyPi can be used, the authors of the paper document its use in a series of “state-of-the-art neurogenetics experiments”, so go check out the recently published open access paper on PLOS. Everything considered the authors hope that the low cost and modular nature, as well as the fully open design of FlyPi, will make it a widely used tool in a range of applications, from the classroom all the way to research labs. Need more lab equipment hacks? Don’t worry, we’ve got you covered. And while you’re at it, why not take a spin with the RWXBioFuge.