fig1

Figure 1. The material design of the injectable conductive hydrogel (ICH) for ECoG electrode. (A) Schematic illustration of ICH-based soft brain interface (gray box, left) and ICH structure: HATYR (biocompatible backbone), PEDOT:PSS (conductive segment with green arrow indicating PSS), and glycerol (hydrophobic segment) (black box, right); (B) MRI-imaging scenarios of (i) ICH-based soft brain interface consisting of ICH and conformable substrate (PVDF-HFP) (left blue box) and (ii) ICH-based soft brain interface, which is composed of ICH and conformable substrate (PVDF-HFP) (right red box); (C) Illustration of ECoG signal recording model to ICH-based soft brain interface (left) and principle of ECoG signal recording from left hemisphere from external stimulation (right). ECoG: electrocorticogram; HATYR: tyramine-conjugated hyaluronic acid; PEDOT:PSS: poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate); PVDF-HFP: poly(vinylidene fluoride-co-hexafluoropropylene).