Nanobots Swim like Scallops in Non-Newtonian Fluids

The idea of using nanobots to treat diseases has been around for years, though it has yet to be realized in any significant manner. Inspired by Purcell’s Scallop theorem, scientists from the Max Planck Institute for Intelligent Systems have created their own version . They designed a “micro-scallop” that could propel itself through non-Newtonian fluids, which is what most biological fluids happen to be.

The scientists decided on constructing a relatively simple robot, one with two rigid “shells” and a flexible connecting hinge. They 3D-printed a negative mold of the structure and filled it with a polydimethylsiloxane (PDMS) solution mixed with fluorescent powder to enable detection. Once cured, the nanobot measured 800 microns wide by 300 microns thick. It’s worth noting that it did not have a motor. Once the mold was complete, two neodymium magnets were glued onto the outside of each shell. When a gradient-free external magnetic field was applied, the magnets make the nanobot’s shells open and close. These reciprocal movements resulted in its net propulsion through non-Newtonian media. The scientists also tested it in glycerol, an example of a Newtonian fluid. Confirming Purcell’s Scallop theorem, the nanobot did not move through the glycerol. They took videos of the nanobot in motion using a stereoscope, a digital camera with a colored-glass filter, and an ultraviolet LED to make the fluorescent nanobot detectable.

The scientists did not indicate any further studies regarding this design. Instead, they hope it will aid future researchers in designing nanobots that can swim through blood vessels and body fluids.  We don’t know how many years it will be before this becomes mainstream medical science, but we know this much: we will never look at scallops the same way again!

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Medical Tricorder Mark I

A handheld tricorder is as good a reason as any to start a project. The science-fiction-derived form factor provides an opportunity to work on a lot of different areas of hardware development like portable power, charging, communications between sensor and microcontroller. And of course you need a user interface so that the values being returned will have some meaning for the user.

[Marcus B] has done a great job with all of this in his first version of a medical tricorder. The current design hosts two sensors, one measures skin temperature using infrared, the other is a pulse sensor.

For us it’s not the number of sensors that makes something a “tricorder” but the ability of the device to use those sensors to make a diagnosis (or to give the user enough hints to come to their own conclusion). [Marcus] shares similar views and with that in mind has designed in a real-time clock and an SD card slot. These can be used to log sensor data over time which may then be able to suggest ailments based on a known set of common diagnosis parameters.

Looking at the image above you may be wondering which chip is the microcontroller. This build is actually a shield for an Arduino hiding underneath.

There’s a demonstration video after the break. And if you find this impressive you won’t want to miss the Open Source Science Tricorder which is one of the finalists for the 2014 Hackaday Prize.

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UC Davis Researchers Use Light to Erase Memories in Genetically Altered Mice

Much like using UV light to erase data from an EPROM, researchers from UC Davis have used light to erase specific memories in mice. [Kazumasa Tanaka, Brian Wiltgen and colleagues] used optogenetic techniques to test current ideas about memory retrieval. Optogenetics has been featured on Hackaday before. It is the use of light to control specific neurons (nerve cells) that have been genetically sensitized to light.  By doing so, the effects can be seen in real-time.

For their research, [Kazumasa Tanaka, Brian Wiltgen and colleagues] created genetically altered mice whose activated neurons expressed GFP, a protein that fluoresces green. This allowed neurons to be easily located and track which ones responded to learning and memory stimuli. The neurons produced an additional protein that made it possible to “switch them off” in response to light.  This enabled the researchers to determine which specific neurons are involved in the learning and memory pathways as well as study the behavior of the mouse when certain neurons were active or not.

Animal lovers may want to refrain from the following paragraph. The mice were subjected to mild electric shocks after being placed in a cage. They were trained so that when they were put in the cage again, they remembered the previous shock and would freeze in fear. However, when specific neurons in the hippocampus (a structure in the brain) were exposed to light transmitted through fiber optics (likely through a hole in each mouse’s skull), the mice happily scampered around the cage, no memory of the earlier shock to terrify them. The neurons that stored the memory of the shock had been “turned off” after the light exposure.

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EM Pulser Flings Washers, Side Effects May Include Curing Cancer or Death

Some folks believe that exposure to electromagnetic pulses helps the human body heal itself (one portion of the [Bob Beck] protocol). [Steffan] is one of those folks and was interested in EMP generation but wasn’t crazy about the several-hundred dollar price tag for professional units. As any determined DIYer would do, he set off to make his own.

This whole thing works by straight-out-of-the-wall 110v AC running through a couple 60 watt light bulbs before moving through a rudimentary rectifier circuit. The DC output from the rectifier charges five 130uF camera flash capacitors. An inductor coil is responsible for generating the EMP and is only separated from the capacitors by a single normally-open momentary switch. Although it is possible to wrap your own coil, [Steffan] decided to use an off the shelf 2.5mH unit normally used for speaker system crossovers. Once the momentary switch is pressed, the energy in the capacitors is discharged through the inductor coil and the EMP is created. To demonstrate that the pulser does indeed work, a metal washer was placed on the inductor coil and the unit fired resulting in the washer being thrown into the air.

[Stephan] did deviate from the some of the online designs he had researched, using 7 capacitors instead of the recommended 5. The result was a firecracker-like discharge sound and melting of the 14 gauge wire. Well, back to 5 caps.

Using a Theremin for Medical Applications

[Eswar] is not an ordinary 16 years old boy. He figured out a noninvasive way to measure breathing in hospitals for less than $50. He is using a theremin to measure the rise and fall of a patient’s chest. For our curious readers, this touch-less instrument was invented back in 1929 by the Russian inventor [Leon Theremin]. It uses the heterodyne principle and two oscillators to generate an audio signal. One electronic oscillator creates an inaudible high pitch tone while another variable oscillator is changed by adding capacitance to an antenna.

As you can guess the space between the patient’s chest and the antennas placed around the bed forms a tiny capacitor which varies when exhaling. With three simple TTL chips and a little guessing [Eswar] had a working prototype ready to be implemented in the real world. If you’re interested in theremin, we invite you to see one of our previous articles on how to make one in a few minutes with a soda can.

THP Semifinalist: fNIR Brain Imager

565281406845688681 The current research tool du jour in the field of neuroscience and psychology is the fMRI, or functional magnetic resonance imaging. It’s basically the same as the MRI machine found in any well equipped hospital, but with a key difference: it can detect very small variances in the blood oxygen levels, and thus areas of activity in the brain. Why is this important? For researchers, finding out what area of the brain is active in response to certain stimuli is a ticket to Tenure Town with stops at Publicationton and Grantville.

fMRI labs are expensive, and [Jeremy]’s submission to The Hackaday Prize is aiming to do the same thing much more cheaply, and in a way that will vastly increase the amount of research being done with this technique. How is he doing this? Using the same technology used in high-tech vein finders: infrared light.

[Jeremy]’s idea is much the same as a photoplethysmograph, better known as a pulse oximeter. Instead of relatively common LEDs, [Jeremy] is using near infrared LEDs, guided by a few papers from Cornell and Drexel that demonstrate this technique can be used to see blood oxygen concentrations in the brain.

Being based on light, this device does not penetrate deeply into the brain. For many use cases, this is fine: the motor cortex is right next to your skull, stretching from ear to ear, vision is taken care of at the back of your head, and memories are right up against your forehead. Being able to scan these areas noninvasively with a device you can wear has incredible applications from having amputees control prosthetics to controlling video game characters by just thinking about it.

[Jeremy]’s device is small, about the size of a cellphone, and uses an array of LEDs and photodiodes to assemble an image of what’s going on inside someone’s head. The image will be somewhat crude, have low resolution, and will not cover the entire brain like an fMRI can. It also doesn’t cost millions of dollars, making this one of the most scientifically disruptive entries we have for The Hackaday Prize.

You can check out [Jeremy]’s intro video below.


SpaceWrencherThe project featured in this post is a semifinalist in The Hackaday Prize. 

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3D Printing a Beautiful Prosthetic Hand for a Stranger

Here’s a story that made us feel all warm and tingly on the inside. [Evan Kuester] is currently studying his Masters in Architecture with a specialty in digital fabrication. His program has access to some nice 3D printers, and he was itching for a good project to use them for. Why not a 3D printed prosthetic hand?

He got the idea after noticing a fellow student on campus who was missing her left hand, and did not have any kind of prosthetic. Eventually he worked up the nerve to introduce himself to her and explain his crazy idea. She thought it was brilliant.

Using Rhino, [Evan] began modeling the prosthetic hand using a plugin called Grashopper. He wanted the hand to be functional as well as aesthetically pleasing, so he spent quite a while working with [Ivania] to make it just right. His first prototype, the Ivania 1.0 wasn’t quite what he imagined, so he redesigned it to what you see above. It’s a beautiful mixture of engineering and art, but unfortunately the fingers don’t move — perhaps an improvement for version 3.0? Regardless of functionality, [Ivania] loves it.

Oh, and [Evan] and [Ivania] are close friends now — in case you were wondering.

[via Make]