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)
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.
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.
There’s an old magic trick known as the miser’s dream, where the magician appears to pull coins from thin air. Australian scientists say they can now generate electricity out of thin air with the help of some enzymes. The enzyme reacts to hydrogen in the atmosphere to generate a current.
They learned the trick from bacteria which are known to use hydrogen for fuel in inhospitable environments like Antarctica or in volcanic craters. Scientists knew hydrogen was involved but didn’t know how it worked until now.
The enzyme is very efficient and can even work on trace amounts of hydrogen. The enzyme can survive freezing and temperature up to 80 °C (176 °F). The paper seems more intent on the physical mechanisms involved, but you can tell the current generated is minuscule. We don’t expect to see air-powered cell phones anytime soon. Then again, you have to start somewhere, and who knows where this could lead?
Microbial fuel cells aren’t new, of course. If you just want lights, you can skip the electricity altogether.
Whether you are trying to drop some fat or build some muscle, it’s important to track progress. It’s easy enough to track your weight, but weight doesn’t tell the whole story. You might be burning fat but also building muscle, which can make it appear as though you aren’t losing weight at all. A more useful number is body fat percentage. Students from Cornell have developed their own version of an electrical body fat analyzer to help track body fat percentage.
Fat free body mass contains mostly water, whereas fat contains very little water. This means that if you were to pass an electrical current through a body, the overall bioelectrical impedance will vary depending on how much fat or water there is. This isn’t a perfect system, but it can give a rough approximation in a relatively easy way.
The students’ system places an electrode on one hand and another on the opposite foot. This provides the longest electrical path possible in the human body to allow for the most accurate measurement possible. An ATMega1284P is used to generate a 50kHz square wave signal. This signal is opto-isolated for user safety. Another stage of the circuit then uses this source signal to generate a 10ua current source at 50kHz. This is passed through a human body and fed back to the microcontroller for analysis.
The voltage reading is sent to a MATLAB script via serial. The user must also enter in their weight and age. The MATLAB script uses these numbers combined with the voltage reading to estimate the body fat percentage. In order to calibrate the system, the students measured the body fat of 12 of their peers using body fat calipers. They admit that their sample size is too small. All of the sample subjects are about 21 years old and have a similar body fat percentage. This means that their system is currently very accurate for people in this range, but likely less accurate for anyone else. Continue reading “DIY Electrical Body Fat Analyzer” →