Leaf Water Content Measurement Using Terahertz Absorbance

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Solution Overview

Problem

Current methods for measuring water content in leaves, such as gravimetric methods, are invasive and time-consuming, while existing terahertz spectroscopy techniques require complex calibration and specialized equipment, making them impractical for non-invasive, field-based measurements.

Innovation Solution

A method using terahertz waves to measure water content in leaves by determining the product of absorbance and projected area, eliminating the need for additional spectroscopic information and employing a portable apparatus with a terahertz quantum cascade laser, lock-in amplifier, and imaging system for precise, non-invasive measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If gravimetric method is used to measure water content, then measurement precision is improved, but measurement time increases and sample destruction occurs

Engineering Contradiction:

Improvewater content measurement precisionVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical gravimetric method (weighing, drying in oven) with terahertz wave-based measurement. The water content is determined by measuring the attenuation of terahertz waves passing through the leaf, eliminating the need for physical drying and weighing operations, thus reducing measurement time while maintaining precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the interaction between terahertz waves and water molecules in the leaf. The attenuation of terahertz radiation is directly related to the water content, leveraging the dielectric properties of water in the terahertz frequency range to enable non-invasive measurement without phase transition processes.

Inventive Principle:

Principle #36Phase transitions

2Loss of time

If terahertz spectroscopy is used to measure water content, then measurement time is reduced, but device complexity and calibration requirements increase

Engineering Contradiction:

Improvemeasurement timeVSAvoidcalibration complexity

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent extracts and measures only the essential parameter (terahertz attenuation) directly related to water content, eliminating the need for additional measurements of refractive index, volume, and other spectroscopic parameters. This single-parameter approach simplifies the measurement system and removes the complexity of multi-parameter calibration.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent creates a direct calibration curve between terahertz attenuation and water content using reference samples. This simplified calibration approach, based on the established relationship between terahertz absorption and water content, replaces the complex multi-parameter calibration required by traditional spectroscopy methods.

Inventive Principle:

Principle #26Copying

3Measurement precision

If multiple-parameter physical models are used in terahertz spectroscopy, then measurement precision is improved, but measurement complexity increases

Engineering Contradiction:

Improveabsolute water content measurement precisionVSAvoidmeasurement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #2Taking out (Extraction)

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 precise, non-invasive, and absolute measurement of water content in leaves without complex calibration, allowing for compact, portable equipment that can be used in the field, reducing complexity and time required for measurements.

Implementation Method 1

subjecting a leaf to terahertz radiation, detecting the terahertz radiation transmitted through the leaf, and determining the water content of the leaf from the detected transmitted terahertz radiation

Methodology Applied

Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP3312590B1A non-invasive method for measuring absolute water content of a leaf

Publication Date: 2020.03.18 CONSIGLIO PER LA RICERCA IN AGRI E LANALISI DELLECONOMIA AGRARIA

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Figure 4a~4c

AI summary

A method for measuring the water content of a leaf by means of terahertz waves, comprising subjecting a leaf (LS) to terahertz radiation, detecting terahertz radiation (TTB) transmitted through the leaf (LS), and determining the water content of the leaf from the detected transmitted terahertz radiation (TTB). The method also includes determining the total projected area A of the leaf. Determining the water content of the leaf (LS) comprises determining the absorbance τ of the leaf from the transmitted terahertz radiation (TTB) detected, determining the product of the absorbance τ with the total projected area A of the leaf and determining the absolute water content Mw of the leaf by comparing the product with a calibration curve that associates water content data with absorbance product data with the projected area of leaves of the same variety.