Optical Biosensors Utilizing Polymer-Based Athermal Integrated Photonic Devices.

Area of Science:

• Photonics
• Materials Science
• Biomedical Engineering

Background:

• Temperature variations destabilize photonic waveguide devices, impacting wavelength-filtering stability.
• Developing temperature-insensitive devices is crucial for reliable optical sensing applications.

Purpose of the Study:

• To develop a polymer-based athermal photonic chip for stable optical biosensing.
• To achieve mutual compensation of thermal optical and thermal expansion effects for temperature insensitivity.

Main Methods:

• Utilized polydimethylsiloxane (PDMS) and poly(methyl methacrylate) (PMMA) as waveguide materials and NOA61 as the substrate.
• Designed an athermal optical demodulator photonic chip incorporating waveguide Bragg gratings.
• Investigated the compensation mechanism between the thermal optical effect and thermal expansion effect.

Main Results:

• Achieved a temperature sensitivity of -13.81-13.4 pm/°C for the photonic sensor.
• Demonstrated blood glucose sensitivity of 208.4 pm/(mg/mL) with 92.766% accuracy (0-1.5 mg/mL).
• Showcased pressure measurement sensitivity of 610 pm/kPa for 0-12 kPa range and a temperature sensor with -207.8 pm/°C sensitivity.

Conclusions:

• The developed athermal photonic chip offers good temperature stability for optical biosensing.
• This cost-effective athermal design using polymer materials shows promise for overcoming wavelength shifts in photonic devices.
• The chip enables accurate physiological measurements, including blood glucose and pressure, under varying temperatures.