A 3D-Printable smartphone accessory for plant leaf chlorophyll measurement

Area of Science:

• Agricultural Science
• Biotechnology
• Optics

Background:

• Leaf chlorophyll content is a key indicator of plant health and nutritional status.
• Accurate chlorophyll measurement is crucial for agricultural management.
• Existing methods can be expensive or inaccessible for widespread use.

Purpose of the Study:

• To develop a low-cost, accessible smartphone-based accessory for estimating leaf chlorophyll content.
• To provide open-source 3D printing files and assembly instructions for the device.
• To validate the accuracy of the developed system against standard chlorophyll measurement techniques.

Main Methods:

• A 3D-printed accessory incorporating a 663 nm LED light source and ambient light sensor was designed for smartphones.
• The accessory measures light transmission through intact plant leaves.
• Readings were compared against spectrophotometric analysis and a SPAD 502™ meter for validation.

Main Results:

• The smartphone-based system accurately estimated leaf chlorophyll concentration in five tropical plant species.
• Performance was comparable to established spectrophotometric and SPAD meter methods.
• The 3D-printable design and open-source nature facilitate widespread adoption.

Conclusions:

• The developed smartphone accessory offers a reliable and affordable tool for chlorophyll estimation.
• This technology can significantly contribute to the adoption of precision farming and digital agronomy.
• Its accessibility supports agricultural practices across various scales.