The Many Reasons For Putting Microphones In Rainforests

If a tree falls in a forest with nobody around, does it make a noise? In the case of the rainforests equipped with the Rainforest Connection’s Guardian system someone most assuredly will.

Rainforest Connection’s Guardian system up close, with microphone visible. (Credit: RFCx)

Originally created by the people behind the US nonprofit Rainforest Connection (RFCx) using upcycled smartphones to detect the sounds of illegal logging, their project now has grown into something much larger, keeping not only tabs on sounds of illegal activity, but also performing bioacoustic monitoring for scientific purposes.

Currently active in ten countries, the so-called Guardian Platform no longer features smartphones, but custom hardware inside an IP66 weatherproof enclosure and a whole range of communication options, ranging from cellular bands to satellite communications. The petal-shaped solar panels provide the module with up to 30 watts of power, and double as a shield to help protect it from the elements.

Not only is the real-time microphone data incredibly useful for rangers trying to stop illegal logging, it also provides researchers access to countless hours of audio data, which will require detailed, automated analysis. Even better is that if the audio data is available to the general public as well, via their Android & iOS apps (bottom of page), just in case you wanted to hear what that sneaky wildlife in the jungle of Peru is up to right now.

Bioadhesive Polymer Semiconductors For In-Vivo Sensors

The bioadhesive electrodes on a roll.
The bioadhesive electrodes on a roll.

What do you do when you want to stick an electrode or even an couple of sensors to an internal organ, such as a heart? Generally you’d use some kind of special adhesive, or sutures to ensure that the item remains firmly in place and doesn’t migrate to somewhere else within the chest cavity or among the intestines. According to a new study (press release) by Nan Li and colleagues in Science there may however be a more elegant method, using bioadhesive polymers.

The double-network copolymer is designed so that once put in the desired location it soaks up moisture and provides a dry interface for its bioadhesive properties. In addition, the resulting material is electrically conductive, with a measured charge-carrier mobility of ~1 square centimeter per volt per second.

Using thus manufactured electrodes were applied to both an isolated rat heart and in vivo rat muscles to measure electrical currents produced by each respective tissue type. The authors of the study envision that using this technology more complicated interfaces and sensors can be developed that would interface directly with organs and related. The claimed biocompatibility would also allow for such devices to be left in-situ for extended periods of time, which could be a boon for a wide range of medical conditions where continuous monitoring is a crucial element.