Brain-computer interfaces (BCIs) often include scalp-applied or even brain-implanted electrodes, serving a variety of beneficial applications. However, if a new, less intrusive BCI is required, it can easily be inserted into the patient's ear canal.

The SpiralE is an experimental device created by a group of researchers from Tsinghua University in China. It is a tiny multilayered rectangular strip that is just 50 mm long and 3 mm broad, comprised of two shape-memory polymer layers, one electrothermal actuation layer, and one EEG(electroencephalogram) layer. The corkscrew-like initial twist of the strip makes it possible to put it quickly and readily into the patient's broader ear canal.

Once the device is in place, an electrical field outside of it is exposed to it, which causes a Joule heating process to occur in the electrothermal actuation layer. The shape-memory polymers in the strip try to return to a flat, uncurled condition as a result of the heat produced, reports New Atlas.

As a result, the strip begins to uncurl, but the inner ear canal walls continue to hold it in a less tightly curled position. Thus, where it can easily pick up electrical impulses from the brain, its EEG electrode layer is placed up against the skin of the ear canal.

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The device was shown to be pleasant to wear for extended periods of time in lab tests, and it demonstrated up to 95% accuracy in detecting volunteers' brain activity. The researchers are hopeful that it may eventually be put to use in applications like monitoring patients' sleep patterns or identifying epilepsy or tiredness.

The study team believes that the SpiralE's simplicity of usage may pave the way for new BCI applications. They foresee the creation of software tools that can translate entire ideas into writing, command virtual and actual world things, and possibly even create enhanced memories.