FIG. 7.2 Neural interface electrode materials. (a) TiN electrode used in neuropixel probe. Reprinted with permission from Fiáth et al., Biosens. Bioelectron. 106 , 86–92 ( 2018 ). Copyright 2018 Elsevier. (b) Microscopy image demonstrating crossover of metal layers (Ti/Au/Ti) and electrode sites. Reprinted with permission from Mercanzini et al., Sens. Actuators A 143 , 90–96 ( 2008 ). Copyright 2008 Elsevier. (c) Optical images of gold and Ir-plated electrode sites before the pulse test experiment. Reprinted with permission from Fomani and Mansour, Sens. Actuators A 168 , 233–241 ( 2011 ). Copyright 2011 Elsevier. (d) Electrochemical deposition of conducting polymer (PEDOT) on the electrode sites and around electro-spun PLLA nanofiber templates as a function of deposition time. Reprinted with permission from Abidian et al., Small 6 , 421–429 ( 2010 ). Copyright 2010 John Wiley and Sons. (e) Photolithographically patterned conducting polymer electrodes. Reprinted with permission from Khodagholy et al., Adv. Mater. 23 (36), H268–H272 ( 2011 ). Copyright 2011 John Wiley and Sons. (f) High magnification image of a surface array with transparent graphene electrode sites. Reprinted with permission from Park et al., Nat. Commun. 5 , 5258 (2014). Copyright 2014 Springer Nature. (g) Optical micrograph of the multi-electrode array device made with carbon nanotube-based pillars. Reprinted with permission from Ben-Jacob and Hanein, J. Mater. Chem. 18 , 5181 ( 2008 ). Copyright 1991 the Royal Society of Chemistry. (h) SEM image of PPy nanotube outgrowth on silicon dioxide showing a diameter outgrowth of 60 µm. Reprinted with permission from Abidian et al., Small 6 , 421–429 (2010). Copyright 2010 John Wiley and Sons. More about this image found in Neural interface electrode materials. (a) TiN electrode used in neuropixel ...