Magnetic-Driven 3D Curvilinear Neural Probe for Minimal Invasive Injury

Recording and stimulation of neural circuits in-vivo at the cellular level are essential for us to understand the function of brain and establishing a brain-computer interface. Due to the relatively complicated patterning and fabrication steps, the neural probes with multi-function stimulation and large-area coverage are usually based on conventional semiconductors such as silicon. The major drawback of these rigid neural probes is it will inevitably damage parts of the brain and induce immune response lead to lead to glial scars which limits the long-term recording.<br/> <br/>In this work, we will present a polymer-based flexible neural probe, based on standard lithography process and 3D printing process. The probe equip with eight closely spaced 30 μm diameter PEDOT:PSS/pHEMA electrode and a soft magnetic polymer fiber shuttle which can be driven by external gradient magnetic field and go into brain with 3D curvilinear path. We designed and fabricated a magnetic actuation platform for controlling the magnetic probe motion and positioning precisely. We also integrated the Fiber Bragg Gratings (FBG) into this neural probe as the feedback of the probe position and shape. In the talk, the operating mechanism and the fabrication process of the magnetic neural probe will also be discussed. This neural probe can minimize the risks of brain damage or glial scaring during neural spike recording and neuron stimulation and have great potential for biomedical applications. As a demonstration, we will also discuss the application of the flexible neural probe in the brain of the rat for the direct neural spike and local field potential sensing.