Study on 3D bio-stimulating microelectrode array based on flexible substrate

A novel 3D bio-stimulating microelectrode array was designed based on polyimide thin film for implantable artificial retina.Non-silicon MEMS technique was applied o fabricate the flexible microelectrode with the height of 80 μm,which is also bio-compatible and chemical stable.The microelectrode was then released from substrate by PDMS sacrificial layer process and packaged by polyimide and PDMS.Au was eletroplated on the surface of electrodes and pads to obtain bio-compatibility.The electrochemical properties of electrodes was detected by three-electrode method,and the impedance varied at the range of 1.5～0.3 kΩ and at the frequency 10-1～105 Hz.With the advantages of small size,light weight,high reliability and flexibility,the device is suitable for bio-stimulation.