Extra-Soft Tactile Sensor for Sensitive Force/Displacement Measurement with High Linearity Based on a Uniform...

Area of Science:

• Robotics
• Materials Science
• Biomedical Engineering

Background:

• Soft sensing systems are crucial for soft robots and healthcare.
• Existing thin-film sensors struggle with linear measurement of normal displacement.
• A need exists for sensors capable of measuring both displacement and force in soft materials.

Purpose of the Study:

• To propose and fabricate novel soft tactile sensors.
• To enable simultaneous measurement of normal displacement and force.
• To overcome limitations of thin-film sensors in linearity for displacement measurement.

Main Methods:

• Development of a theoretical model for uniform-strength cantilever beam sensors.
• Fabrication of the proposed soft tactile sensors.
• Experimental testing to validate the theoretical model and characterize sensing performance.

Main Results:

• The fabricated sensors accurately measure both displacement and force, validating the theoretical model.
• The sensors exhibit ultra-soft properties with low equivalent stiffness (0.31 N·m⁻¹).
• High linearity (R² = 0.999), sensitivity (0.533 pF·mm⁻¹ for displacement, 1.66 pF·mN⁻¹ for force), and low detection limits (70 μm, 20 μN) were achieved.

Conclusions:

• The developed soft tactile sensors offer a new approach for measuring force and displacement in soft objects.
• These sensors demonstrate superior performance characteristics, including linearity and sensitivity.
• Broad application prospects exist in mechanical and medical fields, particularly for soft robotics and healthcare.