A recent article published in the scientific journal NanoLetters discusses a new way to miniaturize batteries for small scale electronics. The work comes from the Stevens Institute of Technology. There are a lot of devices on the drawing board of engineers that are going to require extremely small battery supplies. Examples include biosensors that can be implanted into the body and which need to continue to be powered for years at a stretch. One group of researchers has now developed a new method of handling this power need via the use of piezoelectric materials. This would be of great help if you don’t want your sports betting via https://www.ogdenvalleysports.com/ get interrupted when you are playing on your phone.
I’ve talked before here about the science behind piezoelectric fibers. A piezoelectric material is a substance that generates an electric field when it is physically stressed or flexed. Some piezoelectric materials also work in reverse, in that the application of an electric field causes a physical deformation in the material, but it’s really the first process that is the most interesting for us here. Piezoelectric materials can be quite difficult to prepare, as they require a special alignment of the molecular dipoles present in order maximize the power generated upon application of a physical stress.
The researchers at the Stevens Institute took extremely small piezoelectric fibers – each only about 60 nanometers wide, which means they were 60×10^-9 meters in diameter – and laid them out in an aligned array over fine wires of platinum metal, which served as the electrode. The whole device was built on top of a silicon substrate. When stress was applied in the form of a tiny physical force pressing against the array, electric power began to be generated: an output voltage of just over 1.5 Volts, with a current of 0.03 microWatts. For an extremely tiny device with no moving parts and which will continue to generate power indefinitely as long as physical stresses continue to be applied, this is quite remarkable.
Researchers intend to use this new technology in the area of implantable biomedical devices. For obvious reasons, these devices (such as cameras or diagnostic instruments) have to be extremely tiny, as they’re going to be introduced into a patients body. Also for obvious reasons, there can’t be an external power cord. The devices have to be small and they have to be self-powered. Ideally, the power supply would be one that lasts for years; it’s inconvenient and even dangerous to have to perform fresh surgery every six months simply to replace a dead battery. These new piezoelectric generators are the perfect solution, as they will never stop producing energy. By inserting a device powered by these nanoarrays, gentle motion provided by either the flow of blood in the veins or by the fluid movement in the gastrointestinal tract is more than sufficient to power the piezoelectric fibers and to begin to generate electricity. This allows these miniature electric components to exist in the patients body for extended periods of time, allowing the collection of vast amounts of diagnostic information and images to assist doctors in their diagnosis and treatment.
This is a really, really first-class research paper. Simply miniaturizing the components to this level was a nice achievement, but designing a method to power them using the bodies natural motion was a real kicker. I thoroughly recommend the article and I have no doubt we’ll start to see commercial products utilizing this new technology very soon.