Nano-conductor Composite Electrode for Fingerprint Sensing
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Solution Overview
Problem
The accuracy and sensitivity of capacitive fingerprint recognition are limited due to the difficulty in manufacturing finer nanometer-sized capacitive electrodes, which restricts the precision and reliability of fingerprint recognition.
Innovation Solution
An electrode structure comprising a composite layer made from cured main body glue and one-dimensional nano-conductor materials, where one end of each nano-conductor material is exposed for finger contact and the other end contacts the electrode body, improving contact accuracy with ridge and valley structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If capacitive electrodes are manufactured using traditional mask and etching processes, then the manufacturing process is simple and cost-effective, but the electrode size cannot be reduced below a certain limit, limiting recognition accuracy and sensitivity
Solution Approach 1:
The patent changes the fundamental parameter of electrode structure from traditional planar ITO electrodes to vertically oriented one-dimensional nano-conductor materials (such as carbon nanotubes or metal nanowires) with diameters in the nanometer range. This parameter change enables achieving nanometer-scale precision without requiring complex nanometer-level lithography processes, as the nano-conductors can be grown or assembled vertically to achieve the desired fine dimensions while using relatively simple manufacturing steps.
Solution Approach 2:
The patent employs composite materials consisting of one-dimensional nano-conductor materials (such as carbon nanotubes, metal nanowires, or nanorods) combined with transparent conductive materials like ITO. The nano-conductor materials provide the fine nanometer-scale structure for high precision, while the transparent conductive material ensures electrical conductivity and optical transparency. This composite approach allows achieving both high manufacturing precision and ease of manufacture by combining the advantages of different materials.
2Measurement precision
If capacitive electrodes are made smaller to improve recognition accuracy, then sensitivity increases, but the manufacturing difficulty and cost increase significantly
Solution Approach 1:
The patent transitions from traditional two-dimensional planar electrodes to three-dimensional vertically oriented one-dimensional nano-conductor structures. By growing or assembling nano-conductors perpendicular to the substrate surface, the patent achieves nanometer-scale lateral dimensions (providing high measurement precision for fingerprint recognition) while the vertical orientation allows for simpler fabrication processes that do not require complex nanometer-level lithography, thus reducing manufacturing difficulty and cost.
Solution Approach 2:
The patent changes the critical parameter of electrode lateral size to the nanometer range by using one-dimensional nano-conductor materials with diameters of a few nanometers. This parameter change enables achieving high measurement precision for fingerprint ridge and valley detection while avoiding the need for complex nanometer-level lithography processes, as the nano-conductor dimensions are determined by material synthesis rather than lithographic patterning.
3Ease of manufacture
If traditional ITO electrodes are used, then the structure is simple and manufacturing is easy, but the electrode cannot achieve nanometer size for higher accuracy
Solution Approach 1:
The patent uses composite materials combining one-dimensional nano-conductor materials (such as carbon nanotubes, metal nanowires, or nanorods) with transparent conductive materials like ITO. The nano-conductor component provides the nanometer-scale lateral dimension for high manufacturing precision, while the composite structure maintains electrical conductivity and allows for relatively simple fabrication processes, thus resolving the contradiction between manufacturing simplicity and dimension precision.
Solution Approach 2:
The patent changes the electrode structure from traditional planar ITO films to vertically oriented one-dimensional nano-conductor materials. This parameter change in structure and orientation enables achieving nanometer-scale lateral dimensions with simple manufacturing processes, as the nano-conductor dimensions are controlled by material synthesis rather than complex lithographic patterning, thus simultaneously achieving ease of manufacture and high manufacturing precision.
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
Enhances the accuracy and sensitivity of capacitive fingerprint recognition by allowing precise contact with finger ridges and valleys, overcoming the limitations of traditional capacitive electrodes.
Implementation Method 1
one end of each of the one-dimensional nano-conductor materials is exposed from the finger contact surface of the composite layer, and the other of each of the one-dimensional nano-conductor materials makes contact with the electrode body
Implementation Method 2
the composite layer is made from composite materials formed by a cured main body glue and one-dimensional nano-conductor materials distributed in the main body glue
Data Source
AI summary
Disclosed is an electrode structure including an electrode body, a composite layer disposed on the electrode body; a surface of the composite layer away from the electrode body being set to be a finger contact surface in a case of fingerprint recognition, wherein the composite layer is made from composite materials formed by a cured main body glue and one-dimensional nano-conductor materials distributed in the main body glue; and an end of each of the one-dimensional nano-conductor materials exposed from the finger contact surface of the composite layer, and the other of each of the one-dimensional nano-conductor materials makes contact with the electrode body. A fingerprint recognition module including the electrode structure and a manufacturing method thereof are also disclosed.