Flexible polyimide electrodes

Micromachined flexible, neural electrodes have been designed and manufactured for contacting the tightly packed neural elements in the nerve trunk [30,31], Polyimide was chosen as the substrate and insulation material for a design of multichannel sieve electrodes with integrated interconnects... 

Fig. 9.28. Flexible, polyimide based sieve electrodes interfacing regenerating axons in peripheral nerves...

Rousche PJ, PeUinen DS, Pivin DP, Williams JC, Vetter RJ, Kipke DR (2001) Flexible polyimide-based intracortical electrode arrays with bioactive capability. IEEE Trans Biomed Eng 48(l) 361-370... 

An alternative approach places the Pt electrodes directly on a flexible polymer carrier [80]. Eh Lilly developed a three-electrode transducing system based on a polyimide carrier with electroadsorbed enzyme and a highly oxygen-permeable membrane covering the sensor. Such a system was tested in vivo and published results seem encouraging although the company cancelled the project. 

Thin-film flexible electrodes such as shown in Figure 4.4g have been used for monitoring neonates. They are basically the same as the metal plate electrodes only the thickness of the metal in this case is less than a micrometer. These metal films need to be supported on a flexible plastic substrate, such as polyester or polyimide. The advantage of using only a thin metal layer for the electrode lies in the fact that these electrodes are x-ray transparent. This is especially important in infants, in whom repeated placement and removal of electrodes, so that x-rays may be taken, can cause substantial skin irritation. 

Meng, Y.N., Wu, H.P., Zhang, Y.J., Wei, ZX, 2014. A flexible electrode based on a three-dimensional graphene network-supported polyimide for lithium-ion batteries. J. Mater. Chem. A 2,10842-10846. 

C) Flexible electrode 8x8 matrix printed on polyimide foil after thermal and insulation treatments. (D) Optical micrograph of some Ag lines (width -0.5 mm) and electrodes (diameter 8 mm). 

---