Fiber Microelectrode with Photonic Crystal for Signal Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fiber microelectrodes are not suitable for simultaneous optical and electrical signal transmission due to light signal attenuation and interaction with electrical signals, primarily due to unfavorable thermo-mechanical parameter constellations and insufficient refractive index gradients, leading to significant light losses even with slight fiber curvatures.
Innovation Solution
A fiber microelectrode design featuring a light-conducting core surrounded by a photonic crystal within a glass jacket, with the photonic crystal located within the glass jacket sections, and an electrical conductor embedded within the glass jacket, which minimizes light interaction with electrical signals and maintains low attenuation, allowing for stable simultaneous transmission of optical and electrical signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fiber microelectrodes with embedded wires are used, then electrical signal transmission is achieved, but light signal attenuation increases and interaction between light and electrical signals occurs
Solution Approach 1:
The fiber structure is segmented into distinct functional regions: a light-conducting core for optical signals, a photonic crystal layer for light confinement, and a glass jacket containing electrical conductors for electrical signals. This segmentation separates light and electrical signal pathways to eliminate interaction and reduce attenuation.
Solution Approach 2:
The photonic crystal acts as an intermediary structure between the light-conducting core and the glass jacket with electrical conductors. It provides optical confinement through its periodic structure, preventing light from interacting with electrical signals while allowing electrical conductors to function independently within the glass jacket.
2Loss of energy
If refractive index gradients are increased to reduce light losses, then light guidance improves, but thermo-mechanical parameter constellations become unfavorable
Solution Approach 1:
Instead of relying on continuous refractive index gradients that create manufacturing difficulties, the invention uses a photonic crystal structure with discrete periodic variations in refractive index. This changes the approach from gradient-based confinement to periodic-structure-based confinement, achieving low light loss while maintaining manufacturability through standard fiber drawing processes.
Solution Approach 2:
The fiber employs a composite structure combining different materials with complementary properties: a light-conducting core material optimized for optical transmission, a photonic crystal material providing periodic refractive index modulation, and a glass jacket material accommodating both optical and electrical components. This composite approach achieves superior optical performance without compromising manufacturing.
3Ease of manufacture
If the fiber structure is simplified for ease of manufacture, then production becomes easier, but light guidance properties deteriorate
Solution Approach 1:
The photonic crystal layer serves multiple functions simultaneously: it provides optical confinement for light guidance, acts as a structural barrier between the light-conducting core and electrical conductors, and maintains mechanical integrity during fiber drawing. This multi-functionality achieves reliable light guidance without significantly complicating the manufacturing process.
Solution Approach 2:
The fiber structure employs nested concentric layers: the light-conducting core is nested within the photonic crystal layer, which is in turn nested within the glass jacket containing electrical conductors. This nested architecture achieves complex light guidance properties through systematic layering that can be implemented through sequential material deposition during fiber manufacturing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable and low-attenuation transmission of both optical and electrical signals, enhancing the microelectrode's capability for biomedical applications such as optical stimulation and neuronal interaction measurement with improved spatial selectivity and reduced chemical/biological interactions.
Implementation Method 1
At least one light-conducting core (10) is surrounded by a photonic crystal (20), with the photonic crystal (20) located at least in sections within the glass jacket (30)
Implementation Method 2
In the fiber direction, light can spread almost unhindered. With simple optical fibers, the glass-air transition is sufficient to guide the light in the fiber by means of total reflection
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a fiber microelectrode 1 with at least one light-conducting core 10 and a glass sheath 30 surrounding the light-conducting core 10 with at least one electrical conductor 40. At least one light-conducting core 10 is surrounded by a photonic crystal 20, wherein this photonic crystal 20 is located at least partially within the glass sheath 30.