UCLA Case No. 2015-070
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.
POTENTIAL APPLICATIONS:
• Robotic fingers
• Artificial grip
• Light load sensing
ADVANTAGES:
• Robust to peeling, cracking and fatigue
• Highly flexible
• Simple microfabrication process
• Fully embedded electrical connections
DEVELOPMENT-TO-DATE:
System prototyped.
RELATED MATERIALS:
• Ponce Wong, R. D., Posner, J. D., and Santos, V. J., “Flexible microfluidic normal force sensor skin for tactile feedback,” Sensors and Actuators A: Physical 2012:179:62–69.