Bio-compatible miniature viscosity sensor based on optical tweezers

Area of Science:

• Biophysics
• Biomedical Engineering
• Microfluidics

Background:

• Viscosity is a critical biomechanical property influencing cell and tissue function and pathology.
• Accurate viscosity sensing is crucial for early biomedical diagnosis and health monitoring.
• Existing miniature viscosity sensing methods often lack safety, flexible control, or biocompatibility.

Purpose of the Study:

• To develop a novel, safe, and biocompatible miniature viscosity sensor.
• To leverage optical tweezers and microflows for viscosity detection.
• To create a cellular micromotor capable of sensing ambient viscosity.

Main Methods:

• An indirect optical method was employed using optical tweezers to induce microvortices.
• A target yeast cell was rotated within the microvortex, acting as a cellular micromotor.
• The rotation rate of the cellular micromotor was measured against varying ambient viscosity.

Main Results:

• The cellular micromotor's rotation rate decreased proportionally with increasing ambient viscosity.
• The viscosity sensor demonstrated high safety, flexibility, and biocompatibility.
• The method is material-free and fuel-free, enhancing its applicability.

Conclusions:

• A novel cellular micromotor-based viscosity sensor was successfully constructed.
• This sensor offers a promising tool for in vivo detection of cellular and tissue viscosity.
• The technology has potential applications in diagnosing cellular function and pathological conditions without exogenous materials.