Flexible Microfluidic Sensors for Curved Surfaces

Summary

UCLA researchers in the Department of Mechanical and Aerospace Engineering have developed flexible tactile sensors for curved surfaces that are robust against fatigue and suitable for robotic applications.

Background

Robotic applications, such as artificial fingertips, often require the use of sensors that are uniformly wrapped around a curved for tactile sensing. Traditional flexible sensors, however, are microfabricated using thin films or solid electrical components, making them susceptible to failure due to cracking and fatigue. There is a need to develop new methods to create flexible and robust sensors for curved surfaces.

Innovation

UCLA researchers in the Department of Mechanical and Aerospace Engineering have developed a multilayer capacitive microfluidic normal force sensor. The sensor is composed of multiple layers of soft elastomer microchannels filled with conductive liquid gallium alloy and air pockets. The sensor has a low spatial resolution of ~0.5 mm, can be tuned (based on composition) for the desired sensing range and sensitivity, and performs reliably when wrapped around a curved surface. The sensor have been successfully fabricated and tested to perform reliably, wrapped around a curved surface the size of a human finger (1.575 cm−1), and tolerate a curvature as high as 6.289 cm−1. The sensor provides greater sensitivity at low loads (0.4–4 Hz), suitable for robotic applications where light touch is needed.

Applications

• Robotic fingers
• Artificial grip
• Light load sensing

Advantages

• Robust to peeling, cracking and fatigue
• Highly flexible
• Simple microfabrication process
• Fully embedded electrical connections

State Of Development

System prototyped.

Related Materials

• Wong, Ruben D. Ponce, Jonathan D. Posner, and Veronica J. Santos. "Flexible microfluidic normal force sensor skin for tactile feedback." Sensors and Actuators A: Physical 179 (2012): 62-69.

Patent Status