Modular assembly concept for 3D neural probe prototypes offering high freedom of design and alignment precision.

The new assembly technology developed in this research provides a means to extend planar intracortical neural probes with one-dimensional (1D) and two-dimensional (2D) electrode arrangements into complex three-dimensional (3D) neural probes. The approach is based on novel silicon stacking modules realized using microsystems technologies. With these microcomponents, 3D probes can be assembled flexibly and tailored to the demands of neuroscientific experiments. The manufacturing process of the stacking modules provides the possibility to adjust the electrode spacing in the stacking direction with micrometer precision. The assembly method is demonstrated with 32-channel systems comprising 7-mm-long and 50-µm-thin neural probes. The angular alignment between the neural probes and their stacking modules after assembly as well as the vertical electrode pitch were determined to be about 1° and 353±15 µm, respectively.