CDs are becoming largely obsolete now, thanks to the speed of the internet and the reliability and low costs of other storage media. To help keep all of this plastic out of the landfills, many have been attempting to find uses for these old discs. One of the more intriguing methods of reprurposing CDs was recently published in Nature, which details a process to harvest and produce flexible biosensors from them.
The process involves exposing the CD to acetone for 90 seconds to loosen the material, then transferring the reflective layer to a plastic tape. From there, various cutting tools can be used to create the correct pattern for the substrate of the biosensor. This has been shown to be a much more cost-effective method to produce this type of material when compared to modern production methods, and can also be performed with readily available parts and supplies as well.
The only downside to this method is that it was only tested out on CDs which used gold as the conducting layer. The much more common aluminum discs were not tested, but it could be possible with some additional research. So, if you have a bunch of CD-Rs laying around, you’re going to need to find something else to do with those instead.
Thanks to [shinwachi] for the tip!
Get ready for another step towards our dystopian future as scientists have invented a way to track and monitor what we eat. This 2mm x 2mm wireless sensor can be mounted on to teeth and can track everything that goes into your mouth. Currently it can monitor salt, glucose, and alcohol intake. The sensor then communicates wirelessly to a mobile device that tracks the data. Future revisions are predicted to monitor a wide range of nutrients and chemicals that can get ingested.
It uses an interesting method to both sense the target chemicals and communicate its data. It consists of a sandwich of three layers with the central layer being a biosensor that reacts to certain chemicals. The complete sandwich forms a tiny RFID antenna and when RF signals are transmitted to the device, some of the signal gets absorbed by the antenna and the rest reflected back.
The mechanism is similar to how chromatography works for chemical analysis where certain chemicals absorb light wavelengths of specific frequencies. Passing a calibrated light source through a gas column and observing the parts of the spectrum that get absorbed allows researchers to identify certain chemicals inside the column.
This technology is based on previous research with”tooth tatoos” that could be used by dentists to monitor your oral health. Now this tiny wireless sensor has evolved to monitoring the dietary intake of people for health purposes but we’re pretty sure Facebook is eyeing it for more nefarious purposes too.
The ocean is a hostile environment for man-made equipment, no matter its purpose. Whether commercial fishing, scientific research, or military operations, salt water is constantly working to break them all down. The ocean is also home to organisms well-adapted to their environment so DARPA is curious if we can leverage their innate ability to survive. The Persistent Aquatic Living Sensors (yes, our ocean PALS) program is asking for creative ideas on how to use sea life to monitor ocean activity.
Its basic idea is simple: everyday business of life in the ocean are occasionally interrupted by a ship, a submarine, or some other human activity. If this interruption can be inferred from sea life response, getting that data could be much less expensive than building sensors to monitor such activity directly. Everyone who applies to this research program will have the chance to present their own ideas on how to turn this idea into reality.
The program announced it will “study natural and modified organisms” (emphasis ours.) Keeping an open mind to bio-engineering ideas will be interesting, but adding biohacking to the equation also adds to the list of potential problems. While PALS will keep its research within contained facilities, any future military deployment obviously will not. Successful developments in this area will certainly raise eyebrows and face resistance against moving beyond the lab.
But such possibilities are still far away in a future that many never arrive, as is common with DARPA initiatives. Very recently we talked about their interest in brain stimulation and we’ve been fascinated by many DARPA initiatives before that. If PALS takes off, their living sensor nodes might end up face to face with the open-source underwater glider project that won this year’s Hackaday prize.
Monitoring medical patients remotely 24 hours a day has always proven to be a difficult proposition due the size of the wireless sensors attached to the patient’s body to relay vital signs. A team from Queen’s University Belfast has come up with a solution that utilizes the creeping wave effect. The effect applies to electromagnetic waves as they come into contact with solid objects. While the majority of the waves are absorbed by the object, a small amount move along the surface of the object before they continue their path.
Since most of the signal sent by conventional biosensors is absorbed by the patient’s body, the signal must be strong enough to compensate. The antennas designed by the Queen’s University team, though, focus their broadcast laterally instead of inward and outward, maximizing the amount of waves that will travel along patients’ bodies via the creeping wave effect and minimizing the amount that are absorbed. These antennas are up to 50 times as efficient as conventional antennas of the same size, broadcasting a stronger signal with less power.
The applications to the wireless body area networking, attaching multiple biosensors to patients’ bodies, field are obvious, but this technology could be used in other ways. Since the creeping wave antenna is small and wearable, it could conceivably be used to boost low power communication to PDAs, cellphones, or any other portable wireless product.