A far-field-viewing sensor for making analytical measurements in remote locations

Area of Science:

• Optics and Photonics
• Chemical Sensing
• Biomedical Engineering

Background:

• Remote analytical measurements are crucial for in-situ monitoring in various fields.
• Existing sensors often lack the ability to provide both visual and chemical data simultaneously.
• Gradient index (GRIN) lenses offer unique optical properties for miniaturized imaging systems.

Purpose of the Study:

• To develop and demonstrate a far-field-viewing GRINscope sensor for remote analytical measurements.
• To integrate visual imaging and chemical sensing capabilities into a single fiber-optic device.
• To validate the GRINscope's performance in detecting chemical parameters like pH and oxygen.

Main Methods:

• Fabrication of the GRINscope by affixing a micro-GRIN lens to an optical imaging fiber.
• Immobilization of pH-sensitive polymer layers on the GRINscope's distal end.
• Imaging of pH- and O2-sensitive particles and measurement of fluorescence intensity.

Main Results:

• The GRINscope successfully obtained both visual information and chemical data (pH) from a flowing stream.
• Simultaneous imaging and fluorescence intensity measurements of pH- and O2-sensitive particles were achieved.
• The sensor demonstrated effective analytical measurements in remote locations.

Conclusions:

• The GRINscope sensor is a versatile tool for remote, multi-modal analytical measurements.
• This technology enables simultaneous visual and chemical sensing, expanding the capabilities of fiber-optic sensors.
• The GRINscope holds potential for applications requiring in-situ monitoring in inaccessible or remote environments.