Self-Assembling Flexible 3D-MEAs for Cortical Implants

Current Directions in Biomedical Engineering, vol. 7, pp. 359–362

Abstract

Abstract Flexible Multi Electrode Arrays (MEAs) for neural interfacing reduce the mechanical mismatch between the soft brain tissue and the electrode arrays allowing accurate signal recordings and neural stimulation while reducing inflammatory responses. Many standard manufacturing processes of MEAs are designed for planar structures and the production of three-dimensional structures is challenging. In the present study, shaft structures with one to two circular gold microelectrodes (10 - 20 μm), each on a base polyimide (PI) substrate, were investigated. We describe a fabrication method, with which shafts made from bi-layer PI flip into the third dimension, which is a first step towards spontaneous assembly of electrodes in flexible 3D MEAs for neuroelectronic applications. A lift-up of the shafts was achieved by the contraction of a second PI layer and a steady nitrogen flow during polycondensation. This shrinking PI was structured in pits with a width of 5 - 600 μm. We achieved liftup angles of up to 42 degrees. The shaft structures can be hardened and later be used for neural implantation experiments.

Authors 4

1. Lena Hegel corresponding Aachen Institute of Materials in Electrical Engineering 1

   RWTH Aachen University

   Affiliation as printed

   Institute of Materials in Electrical Engineering 1 (IWE1), RWTH Aachen University, Aachen , Germany

2. Andrea Kauth Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Aachen , Germany

3. Karsten Seidl

   Fraunhofer Institute for Microelectronic Circuits and Systems · University of Duisburg-Essen

   Affiliation as printed

   Fraunhofer Institute for Microelectronic Circuits and Systems, Duisburg, Germany and Department of Electronic Components and Circuits and Center for Nanointegration Duisburg- Essen (CENIDE), University of Duisburg-Essen, Duisburg , Germany

4. Sven Ingebrandt Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University, Aachen , Germany