Fatigue-resistant Photoelastic Soft Materials

Background

Sensors for measuring force or pressure are used in a wide variety of applications in industrial, healthcare and automation. Soft sensors, in particular, are used in applications where only low levels of stress are measured. However, one drawback with current soft sensors, is the long term repeatability and cost. Researchers at Michigan State University and Stony Brook University have developed a new photoelastic polymer-based sensor technology. Upon stretching or compression, the sensor material changes color rapidly within seconds, which can be measured and translated into a 2-dimensional force or pressure measurement. The sensor can be used in a variety of applications such as robotics, where rapid force detection is needed and feedback critical for robot operation, or medical where the touching of tissue or transportation of organs requires extreme care.

Technology

The sensor is based on a unique polymer technology that changes color when stress is applied such as when stretched or compressed. The color change is measured with a camera and directly related to this stress which is numerically translated into a 2-dimensional stress pattern using proprietary software. The system has been tested for 10,000 + cycles with consistent and accurate results over time.

Advantages

Long term fatigue resistance - Ideal mechanical and elastic properties for long-term, repetitive stress sensing - Tunable properties such as stiffness and sensitivity - Robust sensing performance with minimal impacts from ambient humidity

Application

Tactile sensor for soft robotic fingers and grippers - Agricultural robots for sensitive fruit picking - Sensors for life sciences (tissue, organs, etc.) - Smart textiles for sports, wearable health monitoring