Ray Optics Model for Optical Trapping of Biconcave Red Blood Cells.

Area of Science:

• Biophysics
• Optical Physics
• Cell Biology

Background:

• Red blood cells (erythrocytes) are vital for oxygen transport, and their physical property impairments can cause disease.
• Optical tweezers are effective experimental tools for analyzing red blood cell properties.
• Limited theoretical research exists on erythrocyte stability within optical tweezers.

Purpose of the Study:

• To conduct a numerical investigation of red blood cell trapping in optical tweezers.
• To analyze the influence of the red blood cell's biconcave shape on optical forces and torques.
• To explore methods for controlling cell orientation using multiple laser beams.

Main Methods:

• Numerical simulation using the ray optics approximation.
• Analysis of trapping dynamics for single- and dual-beam optical tweezers.
• Investigation of trapping with additional laser beams (third and fourth).

Main Results:

• The biconcave shape of red blood cells is a critical determinant of optical forces, torques, and equilibrium positions in optical traps.
• Numerical simulations demonstrate that adding more trapping beams can control cell orientation.
• The study quanties the optical forces and torques acting on erythrocytes.

Conclusions:

• The biconcave shape significantly impacts red blood cell trapping dynamics in optical tweezers.
• Multiple laser beams offer a controllable method for orienting erythrocytes.
• This research provides a theoretical foundation for experimental studies on red blood cell manipulation.