Ratiometric Upconversion Temperature Sensor Based on Cellulose Fibers Modified with Yttrium Fluoride Nanoparticles

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Traditional thermometers can be sensitive to environmental and electromagnetic interferences.
• There is a need for flexible, non-invasive temperature sensing for wearable health monitoring.

Purpose of the Study:

• To develop a novel optical thermometer utilizing regenerated cellulose fibers and lanthanide-doped upconversion nanoparticles.
• To investigate the thermosensitive properties of YF3: Yb3+, Er3+ nanoparticles embedded in cellulose fibers.
• To demonstrate the potential of this fabric-based thermometer for human skin temperature monitoring.

Main Methods:

• Fabrication of regenerated cellulose fibers incorporating YF3: 20% Yb3+, 2% Er3+ nanoparticles via the Lyocell process.
• Characterization of the optical and thermosensitive properties of the developed material under near-infrared excitation.
• Integration of the cellulose-nanoparticle fibers into a fabric for temperature sensing applications.

Main Results:

• The developed optical thermometer exhibited thermosensitive upconversion emission from Er3+ ions.
• The cellulose-nanoparticle composite demonstrated precise and repeatable temperature measurements in the range of 298-362 K.
• The fabric successfully measured human skin temperature, proving its efficacy for wearable applications.

Conclusions:

• A flexible, electromagnetic interference-resistant optical thermometer was successfully developed using modified cellulose fibers.
• The material offers a promising alternative to conventional thermometers, particularly for wearable health monitoring.
• This technology holds potential for non-invasive, reliable temperature sensing in diverse applications.