Thermal Model of an Omnimagnet for Performance Assessment and Temperature Control

Area of Science:

• Electromagnetics and Thermal Engineering
• Biomedical Device Engineering

Background:

• Omnimagnets enable remote magnetic manipulation of medical implants and microrobots.
• Electrical currents in Omnimagnets cause heating, potentially leading to device failure if insulation melts.
• Understanding heat transfer is crucial for maximizing Omnimagnet performance and safety.

Purpose of the Study:

• To develop and validate a transient heat transfer model for Omnimagnets.
• To determine maximum safe operational parameters (time and current) for Omnimagnets.
• To explore methods for increasing Omnimagnet operational time.

Main Methods:

• A transient heat transfer model incorporating three modes of heat transfer was developed.
• The model was experimentally validated, achieving a normalized root-mean-square error below 4%.
• A parametric study investigated the impact of convective heat transfer and Omnimagnet structure.

Main Results:

• The model accurately predicts Omnimagnet temperature changes and is computationally efficient.
• Calculations provide maximum safe operating time at a given current or maximum safe current for a set time.
• Increasing convective heat transfer enhances maximum operational time.

Conclusions:

• The validated thermal model is essential for safe and efficient Omnimagnet operation.
• The model's state-space representation facilitates real-time control to prevent overheating.
• Optimizing heat transfer is key to extending the operational lifespan of Omnimagnets.