Return
A binary stiffness compliant neural microprobe
DOI:10.1016/j.sna.2023.114759.png)
Abstract
En 中文
Objective: To successfully insert a microprobe into the brain, it must be stiff enough to tolerate the penetration force. In contrast, due to the brain micromotion during the use of the microprobe (operation), the mechanical mismatch between the stiff microprobe and soft surrounding neural tissue leads to tissue damage and, ultimately, the failure of the microprobe. Approach: In this study, an innovative design is proposed to create a binary stiffness compliant neural microprobe. The microprobe and surrounding neural tissue are simulated to calculate the microprobe's equivalent elastic moduli and critical buckling force. Moreover, the induced strain on the tissue by the brain longitudinal and lateral micromotions is investigated based on the finite element method. To evaluate the microprobe's efficiency compared to existing ones, the simulation is replicated for a cylindrical microprobe with the same diameter and length, fabricated from polyimide and coated with a neuro-integrative material. Main results: Based on the obtained results, the proposed microprobe's elastic modulus drops from approximate to 4.2 GPa during insertion to approximate to 40 kPa during operation, depending on the force/motion applied. The corresponding critical buckling force is approximate to 267 mN. The maximum strain on the tissue around the proposed microprobe is approximate to 13% and approximate to 69% less than that of the polyimide microprobe, completely bonded to the surrounding tissue, during the brain longitudinal and lateral motions, respectively. The microprobe is fabricated based on two-photon polymerisation technology, characterised, and inserted into a lamb brain to confirm the feasibility of the proposed design. Significance: The proposed microprobe's stiffness changes independently of its material and the surrounding environment's characteristics.
Keywords:
Neural microprobe
Insertion
Buckling
Brain micromotion
Binary stiffness
Fabrication
Journal
IF:
4.9
Papers:
1.5W
Citations:
3.3W
Organization
Cited Papers
Magnetic Actuation of Flexible Microelectrode Arrays for Neural Activity Recordings
NANO LETTERS
IF9.1

