RECORDING EEG ON HAIRY SCALP WITH FLEXIBLE ANNULAR MICRONEEDLE ARRAY ELECTRODE (A-MAE)

The brain is composed of billions of neurons that transmit information through synapses, constituting a vast spatiotemporal neural network.Electroencephalography (EEG), as the sum of postsynaptic potentials measured on the scalp, is the most widely used non-invasive techniques for researching the brain electrophysiological dynamics.The most common EEG acquisition sensors are wet electrodes, which use conductive gel to reduce contact impedance to realize high-quality recording.However, the tedious skin preparation and impedance optimization process requires professional medical technicians and carry a significant time cost.Microneedle array (MNA) is one of the most effective schemes in dry electrode for high-efficiency and convenient EEG recording [1].However, without the conductive gel, most dry electrodes cannot be applied on hairy regions, which set up a great barrier for wider applications.Based on our previous work [2], we design a novel flexible annular MNA electrode (A-MAE) to address the challenge of EEG recording on hairy scalp.As illustrated in Figure 1, with the clever use of a hair braider, a strand of hair can pass through the hollow center of A-MAE, then the braided hair is folded to press against the back of the electrode for fixation, thus avoiding hair obstruction to the microneedles.