Upgraded Plasma Thruster Is Smaller, More Powerful

When [Jay Bowles] demoed his first-generation ion thruster on Plasma Channel, the resulting video picked up millions of views and got hobbyists and professionals alike talking. While ionic lifters are nothing new, this robust multi-stage thruster looked (and sounded) more like a miniature jet engine than anything that had come before it. Optimizations would need to be made if there was even a chance to put the high-voltage powerplant to use, but [Jay] was clearly onto something.

Fast forward six months, and he’s back with his Mark II thruster. It operates under the same core principles as the earlier build, but swaps out the open-frame design and acrylic construction for a rigid 3D printed structure designed to more effectively channel incoming air. The end result is a thruster that’s smaller and has a lower mass, while at the same time boasting nearly double the exhaust velocity of its predecessor. Continue reading “Upgraded Plasma Thruster Is Smaller, More Powerful”

A clear flexible PCB with a number of gold electrodes on one end. It is wrapped over a black cable to demonstrate its flexibility. A set of dashed white lines goes from one end to a zoomed in image of the circuit structure inset in the top right of the image.

Biohybrid Implant Patches Broken Nerves With Stem Cells

Neural interfaces have made great strides in recent years, but still suffer from poor longevity and resolution. Researchers at the University of Cambridge have developed a biohybrid implant to improve the situation.

As we’ve seen before, interfacing electronics and biological systems is no simple feat. Bodies tend to reject foreign objects, and transplanted nerves can have difficulty assuming new roles. By combining flexible electronics and induced pluripotent stem cells into a single device, the researchers were able to develop a high resolution neural interface that can selectively bind to different neuron types which may allow for better separation of sensation and motor signals in future prostheses.

As is typically the case with new research, the only patients to benefit so far are rats and only on the timescale of the study (28 days). That said, this is a promising step forward for regenerative neurology.

We’re no strangers to bioengineering here. Checkout how you can heal faster with electronic bandages or build a DIY vibrotactile stimulator for Coordinated Reset Stimulation (CRS).

(via Interesting Engineering)

A clear droplet sits on a blue PCB with gold traces. A syringe with a drop of clear liquid sits above the droplet.

Grow Your Own Brain Electrodes

Bioelectronics has been making great strides in recent years, but interfacing rigid electrical components with biological systems that are anything but can prove tricky. Researchers at the Laboratory for Organic Electronics (LOE) have found a way to bridge the gap with conductive gels. (via Linköping University)

Outside the body, these gels are non-conductive, but when injected into a living animal, the combination of gel and the body’s metabolites creates a conductive electrode that can move with the tissue. This is accompanied by a nifty change in color which makes it easy for researchers to see if the electrode has formed properly.

Side-by-side images of a zebrafish tail. Both say "Injected gel with LOx:HRP" at the top with an arrow going to the upper part of the tail structure. The left says "t=0 min" and "Injected with gel GOx:HRP" along the bottom with an arrow going to the lower part of the tail structure. The tail shows darkening in the later image due to formation of bioelectrodes.

Applications for the technology include better biological sensors and enhanced capabilities for future brain-controlled interfaces. The study was done on zebrafish and medicinal leeches, so it will be awhile before you can pick up a syringe of this stuff at your local computer store, but it still offers a tantalizing glimpse of the future.

We’ve covered a few different brain electrodes here before including MIT’s 3D printed version and stentrodes.

DIY Soda Can Battery


It may not be particularly useful to create some makeshift batteries out of soda and soda cans, but it’s a good introduction to electrodes and electrolytes as well as a welcomed break from lemons and potatoes. The gang at [Go-Repairs] lopped off the can’s lid and temporarily set the soda aside, then took steel wool to the interior of the can to remove the protective plastic coating. The process can be accelerated by grabbing your drill and cramming the steel wool onto the end of a spade bit, although pressing too hard might rip through the can.

With the soda poured back in, you can eek out some voltage by clipping one lead to the can and another to a copper coin that’s dunked into the soda. Stringing along additional cans in series can scale up the juice, but you’ll need a whole six pack before you can get an LED working—and only just. The instructions suggest swapping out the soda for a different electrolyte: drain cleaner, which can pump out an impressive 12 volts from a six pack series. You’ll want to be careful, however, as it’s likely to eat through the can and is one lid away from being dangerous.

Stick around for a quick video after the break, and if you prefer the Instructables format, the [Go-Repairs] folks have kindly reproduced the instructions there.

Continue reading “DIY Soda Can Battery”

Open Source Neural Activity Monitors

Yesterday we linked to an OCZ Neural Acutator Interface teardown. Several in the comments wanted to know more about the sensor electrodes. Check out the OpenEEG project and OpenEEG mailing list for information on sensing, amplifying, and recording brain activity (EEG). The OpenEEG project maintains an open source Simple ModularEEG design. Two other open source variants of the ModularEEG are the MonolithEEG and [Joshua Wojnas’] Programmable Chip EEG BCI. All three projects use Atmel microcontrollers, with designs in Cadsoft Eagle.

Brain activity is measured using passive or active electrodes. Passive electrodes require a conductive paste to make proper contact with the skin (examples: 1, 2). Active EEG sensors don’t need conductive goop because they have an amplifier directly on the electrode (examples: 1, 2, 3).

[via anonymous reader, comments]