Design methods for constant force mechanisms: An overview of developments and future directions

Area of Science:

• Biomedical Engineering
• Mechanical Engineering
• Materials Science

Background:

• Constant force mechanisms are vital in industry but pose risks in medicine due to potential soft tissue damage from excessive clamping pressure.
• Existing designs like springs and compliant mechanisms face limitations in miniaturization and biocompatibility for delicate medical applications.

Purpose of the Study:

• To review existing constant force mechanism designs and identify limitations for medical applications.
• To explore novel design strategies for safe and effective medical clamping devices.

Main Methods:

• Comprehensive literature review of constant force mechanisms across databases (Google Scholar, ScienceDirect, IEEE Xplore).
• Analysis of traditional methods including springs, pulleys, and compliant mechanisms.
• Investigation of emerging designs integrating shape memory alloys (SMAs) with structural optimization.

Main Results:

• Traditional designs exhibit limitations in achieving necessary miniaturization and adaptability for the human body.
• The combination of SMAs and structural optimization presents a promising solution for reduced complexity, weight, and size.
• This novel approach enhances suitability for intricate medical environments requiring consistent force output.

Conclusions:

• Emerging SMA-based designs offer significant advantages over traditional mechanisms for medical clamping devices.
• This approach paves the way for developing safer, more effective, and miniaturized medical clamping solutions.
• Further development in SMA integration can revolutionize medical device design.