In the field of neuroengineering rehabilitation, from spinal cord injury repair to brain nerve function reconstruction, traditional materials face challenges such as insufficient biocompatibility, poor mechanical matching, and low signal transmission efficiency. With excellent biocompatibility, tunable mechanical properties, and stable dielectric characteristics, silicone rubber and silicone oil have become the "molecular bridge" connecting biological nerves and artificial systems. From neural conduit regeneration guidance to tactile feedback of bionic prosthetics, from long-term implantation of brain-computer interfaces to precise regulation of neural electrical stimulation, they are solving key problems in neurorehabilitation through material innovation.

一、Material Challenges in Nerve Repair

（一）Dual Demands of Bio-Artificial Interfaces

Nerve regeneration requires materials to meet both biocompatibility and functional guidance, while traditional materials have three major bottlenecks:

Immune rejection reaction: Inflammatory cell infiltration rate exceeds 60% after implantation of common polymer materials, leading to fibrous encapsulation.

Mechanical mismatch damage: The elastic modulus of metal prosthetics differs from nerve tissue by over 1,000 times, causing chronic mechanical damage.

Severe signal attenuation: Impedance fluctuation of traditional electrodes exceeds 50%, leading to distortion in neural signal acquisition.

Silicone rubber and silicone oil break through limits via molecular design: The cell adhesion rate of silicone rubber reaches 95% after surface hydroxylation, and silicone oil as a coupling medium reduces the impedance of electrode-nerve interfaces by 70%, achieving seamless integration of bio-artificial systems.

（二）Precision Manufacturing Demands for Dynamic Adaptation

Dynamic deformation of nerve tissue requires materials with bionic mechanical properties, which silicone rubber achieves through special processes:

Gradient elastic molding: The elastic modulus of 3D-printed silicone rubber nerve conduits gradually changes from 10MPa to 0.5MPa from outside to inside, matching the growth environment of nerve fibers.

Nanometer-level surface modification: The silicone rubber surface etched with 100nm grooves increases the directional growth rate of axons by 3 times.

Degradable-non-degradable composite: The composite structure of degradable silicone rubber in the core and long-acting silicone rubber in the outer layer realizes material function switching after nerve regeneration.

二、Silicone Rubber: Structural Support and Functional Guidance for Nerve Regeneration

（一）Bionic Design Breakthroughs of Nerve Conduits

Silicone rubber dedicated to nerve repair achieves performance leaps through triple optimization:

Bionic matrix construction: Silicone rubber introducing type I collagen mimic epitopes increases Schwann cell proliferation rate by 80%. In a spinal cord injury repair experiment, the axon regeneration density of the silicone rubber conduit group was 2.3 times that of the control group.

Vascularization induction: Porous silicone rubber has a porosity of 70% and pore size distribution of 50-100μm, with a blood vessel ingrowth rate exceeding 90% within 4 weeks after implantation.

Electrical signal coupling: Carbon nanotube-silicone rubber composite conduits have an electrical conductivity of 10S/m, enabling real-time monitoring of electrophysiological activities during nerve regeneration.

In clinical applications, a silicone rubber nerve conduit developed by a medical team increased the motor function recovery score of peripheral nerve injury patients from 2.1 to 4.7 (out of 5), with a sensory function recovery rate of 78%.

（二）Interface Innovations of Bionic Prosthetics

Silicone rubber solves multiple challenges in the interaction interface between prosthetics and the human body:

Tactile bionic skin: Silicone rubber epidermis added with micro-structured protrusions has a tactile resolution of 0.1mm, capable of identifying fine textures such as coin patterns.

Mechanical buffering system: The honeycomb silicone rubber cushion has an energy absorption efficiency of 92%. After a bionic arm adopted this design, the wearer's fatigue sensation decreased by 60%.

Bioelectrical signal enhancement: Silicone rubber surface-modified with silver nanowires increases the signal-to-noise ratio of myoelectric signals by 4 times, improving prosthetic control accuracy from 65% to 91%.

三、Silicone Oil: Conduction Medium and Functional Regulation of Neural Signals

（一）Precise Regulation of Neural Electrical Stimulation

Silicone oil demonstrates unique advantages in deep brain stimulation (DBS) systems:

Dielectric constant optimization: The dielectric constant of silicone oil is regulated to 3.2±0.3, with a high-frequency neural signal (1000Hz) attenuation rate < 15%. After a Parkinson's treatment device adopted it, stimulation energy efficiency increased by 35%.

Long-term stability: Fluorosilicone oil shows a viscosity change rate < 3% after soaking in cerebrospinal fluid for 5 years, ensuring long-term stability of stimulation parameters.

Thermal management capability: Silicone oil has a thermal conductivity of 0.3W/m·K, controlling electrode operating temperature below 38°C to avoid thermal damage to nerve cells.

（二）Long-Term Protection for Brain-Computer Interfaces

Silicone oil plays a key role in implanted brain-computer interfaces:

Interface impedance stability: The interface impedance fluctuation of silicone oil-filled electrode arrays is < 10%. A clinical experiment shows that signal acquisition stability of patients using silicone oil lasts for over 24 months.

Immune response suppression: Silicone oil with surface-grafted PEG reduces protein adsorption by 70%, and the thickness of fibrous capsules decreases from 200μm to 50μm.

Mechanical impact buffering: The viscous damping coefficient of silicone oil reaches 0.05Pa·s, buffering electrode micro-displacement caused by head movement and reducing the risk of neuron damage by 80%.

四、Future Innovation Directions of Neurorehabilitation Materials

（一）R&D of Intelligent Response Neural Interface Materials

Researchers are developing multimodal responsive silicone rubber:

Electro-chemical dual response: Silicone rubber embedded with Prussian blue nanoparticles can real-time change light transmittance in response to electrochemical changes induced by nerve impulses, achieving optical visualization of neural activities.

Growth factor sustained release: Microencapsulated silicone oil releases growth factors such as BDNF on demand during nerve regeneration, increasing axon regeneration speed by 50% in an animal experiment.

Self-assembled interface: The dynamic covalent bond network on the silicone rubber surface can form nanoscale connections with nerve cell membranes after implantation, increasing signal transmission efficiency by 3 times.

（二）Performance Breakthroughs of Neuroengineering-Dedicated Silicone Oil

Through molecular design optimization, new silicone oils achieve performance leaps in neurorehabilitation:

Ion channel simulation: Silicone oil added with crown ethers can selectively permeate Na⁺/K⁺ ions, simulating the ion transport characteristics of nerve cell membranes for artificial synapse construction.

Quantum dot coupling: CdSe quantum dots dispersed in silicone oil can convert neural electrical signals into fluorescent signals, enabling multimodal neural activity monitoring.

Bioelectronic compatibility: Silicone oil surface-modified with phospholipid molecules has a fusion efficiency of 90% with neuron cell membranes, suitable for constructing cell-chip interfaces.

（三）Material-Algorithm Collaboration in Nerve-Machine Fusion Systems

Cross-innovation between machine learning and materials science is reshaping neurorehabilitation:

Personalized prosthetic design: AI algorithms based on patients' nerve distribution optimize the mechanical parameters of silicone rubber prosthetics, shortening the prosthetic control learning time from 4 weeks to 1 week in a case.

Closed-loop stimulation regulation: Silicone oil sensors real-time monitor nerve status and feedback to stimulators, forming a closed-loop system of "perception-decision-execution", increasing stimulation accuracy by 70%.

Digital twin model: Establishing a virtual simulation platform for silicone rubber nerve conduits to predict the nerve regeneration trajectories of different patients and guide clinical protocol formulation.

From spinal cord injury repair to brain nerve function reconstruction, silicone rubber and silicone oil are driving the neuroengineering rehabilitation revolution through material innovation. They are not only the "structural support" for nerve regeneration but also the "functional medium" for human-machine integration. With the deep integration of neuroscience and material technology, these silicon-based materials will create more miracles in frontier fields such as amyotrophic lateral sclerosis treatment, coma arousal, and cognitive enhancement—bringing hope for new life to patients with nerve dysfunction and helping humanity break through the functional limits of biological organisms.


Silicone Rubber for ultra-high voltage cable-Mingyi Silicone