A Miniature Soft Sensor with Origami-Inspired Self-Folding Parallel Mechanism.

Area of Science:

• Robotics
• Materials Science
• Sensor Technology

Background:

• Miniature soft sensors are essential for soft robot perception.
• Existing centimeter-scale sensors are well-developed, but millimeter-scale, 3D-shaped sensors for multi-axis force measurement are scarce.

Purpose of the Study:

• To develop a millimeter-scale, 3D-shaped soft sensor capable of measuring multi-axis forces.
• To utilize liquid metal printing and self-folding origami for sensor fabrication.

Main Methods:

• Developed a millimeter-scale (6 mm × 11 mm × 11 mm) soft sensor using liquid metal printing.
• Incorporated a self-folding origami parallel mechanism for 3D shape formation and two-axis rotation.
• Utilized shape-memory polymer and magnets for autonomous sensor self-folding (17 seconds).

Main Results:

• The soft sensor achieved self-folding and a maximum tip deformation of 20 mm.
• Demonstrated the capability to measure external loads in six directions.
• Showcased underwater sensing ability with a minimum sensitivity of 20 mm/s water flow.

Conclusions:

• The developed millimeter-scale soft sensor offers a novel manufacturing method for 3D-shaped sensors.
• This technology provides insights for future millimeter-scale soft sensors, particularly for bio-inspired robots.
• The sensor's multi-axis force sensing and underwater capabilities open new avenues for soft robotic applications.