Organic Semiconductors Providing New Solutions for Future Medical Implants

Although implantable medical microsystems like painkillers, deep brain stimulators and the promising cochlear implants, have reached a high degree of reliability and usability for the patient, the implementation of neural stimulators with hundreds or thousands of microelectrodes still suffers by the interconnection problem between the electrode array and the electronic stimulator device. A mechanically flexible interconnection of all electrodes of a large 2D-electrode array to a monolithically integrated stimulator/recorder device is almost impossible, since the integrated circuit can only be attached using either bumps or bonds. In this contribution, the usage of organic semiconductors for the implementation of an addressable active stimulator cell is proposed to overcome these limitations. This stimulator electronic can be fabricated either with printable long chain organic semiconductors or, as described here, with short chain semiconductors (oligomers) like pentacene. The mechanical flexibility of arbitrarily sized and shaped 2D multicontact array is completely preserved, if this flexible semiconductor electronic is interlaced between the electrode rows and columns.