ETD

• biodegradable stiffener
• flexible intra-cortical electrodes
• sinusoidal multi-channeled electrodes

Neurological impairments and degenerative diseases heavily affect the quality of daily life.
With the aim of establishing an intimate connection with the nervous system the clinical use of implantable devices tremendously increased in the recent past. Invasive neural electrodes, able to properly stimulate neural activity or to record high quality neural signals, are increasingly used for deep brain stimulation and brain-computer interfaces.
However, despite the wide-spread application of these devices, their chronic use is still hampered by technological limitations. One of the hypotheses considers the mechanical mismatch between brain tissue and microelectrodes as a key factor for the inflammatory reaction and foreign body response (FBR) that insulate the electrode from the nervous tissue.
Aim of this work was to ideate and develop novel designs for flexible intra-cortical electrodes able to improve the integration and long-term performance of these devices in the brain cortex.
Combining the polyimide properties with the layouts geometric ones, we manufactured MUlti-branched and Sinusoidal polymer-based Electrodes (MUSE).
A biodegradable and biocompatible stiffener was then developed to allow an easy electrode insertion in the brain. Two FDA-approved materials (starch and PEG) were combined and used to manufacture a sharp arrow-like stiffener.
Electrodes insertion tests in agar-based brain phantom showed promising results and demonstrated the suitability of this approach paving the way for future in vivo testing.