Triboelectric Nanosensor With Liquid Metal for Self-Powered Gait Measurement

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Solution Overview

Problem

Existing gait measurement technologies, such as force plates and traditional gait sensors, lack real-time monitoring and require external power sources, and triboelectric nanosensors face issues with signal deviation due to surface tension adhesion.

Innovation Solution

A triboelectric nanosensor with an elastic body and biomimetic shark placoid scale-shaped microstructures, incorporating a liquid metal and wire, which generates signals through deformation, allowing self-powering and reducing adhesion for stable output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If traditional gait sensors (resistance-type or voltage-type) are used, then gait measurement can be performed, but an outer power source is required which becomes a problem for long-term measurement

Engineering Contradiction:

Improvepower source requirementVSAvoidlong-term measurement capability

Core Design Contradiction:

Use of energy by moving objectVSDuration of action of moving object

Solution Approach 1:

The triboelectric nanosensor generates its own power through triboelectric effect during gait measurement, eliminating the need for external power sources. The sensor harnesses mechanical energy from foot movement to generate electrical signals, enabling self-powered long-term monitoring.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent transforms the sensor operating mode from passive (requiring external power) to active (self-powered) by changing the energy generation mechanism. This parameter change enables continuous long-term measurement without battery replacement or recharging.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If triboelectric nanosensors are used for self-powered measurement, then power independence is achieved, but surface tension causes adhesion between solid and liquid surfaces generating signal deviations

Engineering Contradiction:

Improveself-powering capabilityVSAvoidsignal accuracy

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent extracts and eliminates the harmful adhesion effect caused by surface tension. By removing the liquid component that causes adhesion, the sensor maintains self-powering capability while achieving accurate signal output without deviation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of liquid adhesion into a beneficial dry contact mechanism. The solid-solid triboelectric contact eliminates adhesion issues while maintaining the self-powered advantage, turning a potential problem into a solution.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If force plate is used for gait measurement, then high measuring accuracy is achieved, but real-time monitoring and long-term continuous measurement are not possible

Engineering Contradiction:

Improvegait measurement accuracyVSAvoidreal-time monitoring capability

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces the complex mechanical force plate system with a lightweight triboelectric nanosensor that can be integrated into footwear. This substitution maintains measurement accuracy while enabling real-time monitoring and long-term continuous gait analysis in natural settings.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The triboelectric nanosensor integrates multiple functions: it provides accurate gait measurement, real-time monitoring, and long-term continuous operation in a single device. The sensor can be worn continuously in shoes, making it universally applicable for various gait analysis scenarios.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 real-time, self-powered gait measurement with improved accuracy and stability, capable of distinguishing normal and abnormal gaits by comparing time ratios of foot contact points.

Implementation Method 1

The elastic body is pressed to be deformed and restores to change a contact state between the liquid metal and the biomimetic shark placoid scale-shaped microstructures, thereby allowing a plurality of electrons to flow into the liquid metal via the wire or to flow out from the liquid metal via the wire

Methodology Applied

Scientific EffectTriboelectric effect: Triboelectric Effect

Data Source

PatentUS12433365B2Triboelectric nanosensor and gait measurement method

Publication Date: 2025.10.07 NATIONAL TSING HUA UNIVERSITY

AI summary

A triboelectric nanosensor includes an elastic body, a liquid metal and a wire. The elastic body includes an inner wall surrounding a chamber, and a plurality of biomimetic shark placoid scale-shaped microstructures adjacent to each other and disposed at at least one portion of the inner wall. The liquid metal is located within the chamber and surrounded by the elastic body. The wire is electrically connected to the liquid metal. The elastic body is pressed to be deformed and restores to change a contact state between the liquid metal and the biomimetic shark placoid scale-shaped microstructures, thereby allowing a plurality of electrons to flow into the liquid metal via the wire or to flow out from the liquid metal via the wire.