A method for constructing a conductive substrate soft interface, a microelectrode and its application

Abstract

The invention discloses a construction method, a microelectrode and an application of a soft interface of a conductive substrate. The construction method includes the following steps: providing a conductive substrate; forming a sacrificial metal layer on the surface of the conductive substrate; Constructing a soft interface; wherein, constructing a soft interface specifically includes: providing a conductive polymer electrolyte, placing the conductive substrate formed with a sacrificial metal layer in the conductive polymer electrolyte; applying a potential to make the sacrificial metal in the sacrificial metal layer It is oxidized to ionic state and enters the conductive polymer medium in the conductive polymer electrolyte. The metal ions and the conductive polymer medium form a conductive gel soft interface on the surface of the conductive matrix under the electrified state. The present invention aims to avoid the large mismatch between the soft tissue in the body and the hard coating of the electrode.

Description

technical field [0001] The invention relates to the technical field of microelectrode surface modification, in particular to a method for constructing a soft interface of a conductive substrate, a microelectrode and its application. Background technique [0002] Neural interfaces provide a window for the recording of biological signals and neural stimulation, etc., which can be achieved by using microelectrodes as a bridge between tissues and external devices. With the development of neural electrodes towards integration and miniaturization, we can improve the performance of electrodes by surface modification of electrodes, such as noble metal nano-coating (Pt, Ir, etc.). Several typical materials can be summarized as follows: 1. Platinum black coating (J.Neural Eng.12(2015) 026010) is deposited on the electrode surface. This coating has the advantage of being loose and porous and can significantly reduce the electrochemical impedance of the electrode. It contains toxic add...

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Problems solved by technology

Several typical materials can be summarized as follows: 1. Platinum black coating (J.Neural Eng.12(2015) 026010) is deposited on the electrode surface. This coating has the advantage of being loose and porous and can significantly reduce the electrochemical impedance of the electrode. Contains toxic additives such as lead, which seriously affects its application safety

2. Deposit a layer of rough or irregular platinum coating on the surface of the electrode to replace the platinum black coating (US Patent 7887687, 2011). Although the platinum coating has a certain rough coating, its electrochemical impedance is still high and its charge storage capacity is low. low, which limits its stimulation efficiency

3. The combination of conductive polymers and carbon nanotubes (Nano letters, 9 (2009) 4012-4018) can improve its charge storage and injection capabilities to a certain extent, but the stability is poor. During ultrasonic or electrochemical stimulation Easy to fall off

4. In addition, boron-doped diamond coating (Biomaterials, 53 (2015) 173-183) has a certain effect on improving electrochemical performance, but its high time and economic cost are not conducive to its clinical application

[0003] The above-mentioned modification methods have advantages and disadvantages, but the common disadvantages are: the surface of the electrode is a hard coating (metal or non-metal), which leads to a huge mismatch between the soft tissue in the body and the hard coating of the electrode, resulting in poor stability; The degradation of the coating in the body limits its long-term performance; after multiple stimulations, the electrical activity of the material will be greatly reduced; in addition, mechanical delamination will also lead to poor adhesion between the coating and the electrode; in addition, coating Layer failure-induced tissue responses at neural interfaces remain a serious concern

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