Neurotech’s biggest hurdle is hair. In order to derive a signal that is adequate for inference, electrodes must touch your skin. This is a huge issue in neurotech, as hair makes it extremely difficult to touch the scalp and capture accurate biosignals. This, along with motion artifacts from hair strands makes it hard for newbies to get involved in neurotech, without strenuously studying signal processing pipelines, or exploring machine learning.

Previous attempts have tried to solve this problem by creating conductive spike electrodes that are meant to glide past the hair. Although this partially fixes the problem, it creates more down the line. One of these problems is that comfort is decreased because the electrode rests on the scalp with a couple of spikes. Secondly, a helper is usually required for set up to make sure that the spikes don’t grab the hair and actually go through it. This decreases the overall usability of the product since it cannot be worn for too long, and requires assistance in setting up. However, the problem that trumps these two is that these spike electrodes still do not work on individuals with thick hair.

This is where the innovative solution from the students at the University of Calgary steps in. They are designing a soft-tipped active spike electrode which works on a multitude of hair types. Their material of choice is a conductive silicone polymer which has flexible properties. This is paired with a narrow-spike design which allows for the spike to wedge itself in between hair fibers. Once contact is made with the scalp, the spikes flair out which increases the contact area, reducing the contact resistance and pressure. This not only increases comfort, but improves the signal quality. 

This new electrode material and design will be paired with active amplification circuitry, which further reduces the electromagnetic interference, and improves signal quality.

Follow along as these students enter the final stage development where they will use this new active electrode to make a brain-computer interface.