Carbon Nanotube Electrostatic Sensing for Hover Detection

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Solution Overview

Problem

Current touch panels lack the ability to recognize hover events using electrostatic sensing, which is essential for advanced user interactions in modern electronic devices.

Innovation Solution

An electrostatic sensing device comprising a substrate with ultra-long single-walled carbon nanotubes or few-walled carbon nanotubes as electrostatic sensing elements, which change resistance in response to electrostatic charges, allowing for the detection of objects near but not touching the panel, enabling the recognition of hover events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional touch panel sensing methods are used, then basic touch detection is achieved, but hover event recognition capability is lost

Engineering Contradiction:

Improvehover event recognition capabilityVSAvoiddetection accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the electrical parameter of the sensing element by using ultra-long single-walled carbon nanotubes with length greater than 100 micrometers. This parameter change enables the sensing element to detect both touch and hover events through resistance variations, thereby improving adaptability while maintaining detection reliability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs carbon nanotube material with specific structural characteristics (ultra-long, single-walled or few-walled) as the sensing element. This composite material approach provides both the sensitivity needed for hover detection and the stability required for reliable operation, resolving the contradiction between versatility and reliability

Inventive Principle:

Principle #40Composite materials

2Measurement precision

If ultra-long carbon nanotubes are used as sensing elements, then hover event detection sensitivity is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvehover detection sensitivityVSAvoidsensing element fabrication

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces conventional mechanical or capacitive sensing mechanisms with carbon nanotube-based electrical resistance sensing. This substitution enables high-precision hover detection through electrical property changes while allowing for simpler fabrication processes using established carbon nanotube deposition techniques

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

By specifying carbon nanotubes with length greater than 100 micrometers, the patent optimizes the sensing element parameters to achieve high hover detection sensitivity. This parameter specification works with existing carbon nanotube growth and deposition technologies, thereby managing manufacturing complexity while improving measurement precision

Inventive Principle:

Principle #35Parameter changes

3Reliability

If carbon nanotube sensing elements are implemented, then electrostatic sensing capability is enhanced, but device cost increases

Engineering Contradiction:

Improveelectrostatic sensing capabilityVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces complex electrostatic sensing systems with carbon nanotube-based resistance sensing. This substitution enhances electrostatic sensing capability through the unique electrical properties of carbon nanotubes while potentially reducing overall system cost by eliminating additional components and simplifying the sensing architecture

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

The device effectively detects and distinguishes between touch and hover events by measuring resistance changes, providing superior sensitivity and accuracy for touch panel operations.

Implementation Method 1

an electrostatic sensing element (124) having two opposite ends

Methodology Applied

Scientific EffectElectrostatic sensing: Electrostatics

Implementation Method 2

measuring a resistance changed value of the electrostatic sensing element (124) in response to the sensed object being near

Methodology Applied

Scientific EffectElectrical resistance change: Electrical Resistance

Data Source

PatentUS10386983B2Electrostatic sensing device

Publication Date: 2019.08.20 HON HAI PRECISION INDUSTRY CO LTD

AI summary

An electrostatic sensing device comprises an electrostatic sensing module and a control unit electrically connected to the electrostatic sensing module. The electrostatic sensing module comprises a first electrostatic sensing element comprising opposite ends, and two first electrodes. The two first electrodes are separately located on and electrically connected to the two opposite ends of the first electrostatic sensing element. The first electrostatic sensing element is a single walled carbon nanotube or a few-walled carbon nanotube. The control unit electrically is configured to apply a direct voltage to the first electrostatic sensing element and measure a current/resistance of the first electrostatic sensing element.