Biodegradable Temperature Sensors with Enhanced Sensitivity Using Bioderived Ionic Liquid with Sodium Ions.

Area of Science:

• Materials Science
• Biomedical Engineering
• Electrochemistry

Background:

• Gels offer flexible sensors for electronic and ionic skins, ideal for biomedical monitoring due to skin affinity.
• Bioderived ionic liquids and gels have favorable properties like low vapor pressure, high conductivity, and biodegradability for transient electronics.
• Low temperature coefficient of resistance (TCR) in bioderived ionic liquids limits their use in wearable devices, implants, and environmental sensing.

Purpose of the Study:

• To enhance the TCR of bioderived ionic liquids for biodegradable temperature sensors.
• To investigate the effect of sodium (Na) ion doping on the TCR of choline lactate.

Main Methods:

• Doped sodium (Na) ions into bioderived ionic liquid choline lactate.
• Formulated an ionic gel using Na-doped ionic liquid and poly(vinyl alcohol).
• Characterized the thermal properties, activation energy, and TCR of the ionic gel.
• Assessed the biodegradability of the temperature sensor in a phosphate-buffered solution.

Main Results:

• Na ion doping improved the coupling of choline and lactate, leading to enhanced intermolecular interactions and a higher TCR in the ionic liquid.
• The resulting ionic gel exhibited a high thermal index (7563 K), activation energy (1303 meV), and a significant TCR (8.4%/K).
• The biodegradable temperature sensor degraded over 48 days, leaving the encapsulation layer intact.

Conclusions:

• Sodium ion doping is an effective strategy to enhance the TCR of bioderived ionic liquids for sensitive temperature sensing.
• The developed biodegradable ionic liquid-based temperature sensor shows promise for applications in healthcare, wearable technology, and environmental monitoring.
• This study provides valuable insights for designing advanced ionic liquid-based sensors with improved sensitivity and tailored degradation profiles.