Inverted and vertical climbing of a quadrupedal microrobot using electroadhesion

Area of Science:

• Robotics
• Micro-robotics
• Adhesion Science

Background:

• Climbing ability significantly expands the operational workspace for terrestrial robots, especially for inspection and exploration.
• Millimeter-scale legged robots are desirable for operation in confined environments, but climbing capabilities are limited.

Purpose of the Study:

• To present the Harvard Ambulatory MicroRobot with Electroadhesion (HAMR-E), a novel microrobot designed for climbing vertical and inverted surfaces.
• To demonstrate the utility of HAMR-E for inspection tasks in challenging industrial environments.

Main Methods:

• Design and fabrication of a 1.48-gram, 4.5-cm quadrupedal microrobot with integrated electroadhesive pads and passive alignment ankles.
• Development of a parametric tripedal crawling gait for controlled locomotion.
• Testing of vertical, inverted, and horizontal locomotion capabilities at various adhesion voltages.

Main Results:

• HAMR-E achieved repeatable and reliable climbing on vertical and inverted surfaces using voltage-controlled electroadhesion.
• At 250 volts, HAMR-E reached speeds of 1.2 mm/s (vertical) and 4.6 mm/s (inverted), with up to 215 (162) steps.
• The robot maintained high-speed horizontal locomotion at 140 mm/s.
• Demonstrated inverted locomotion within a commercial jet engine's curved section.

Conclusions:

• The HAMR-E microrobot successfully demonstrates robust climbing capabilities on challenging surfaces.
• Its design innovations and locomotion strategies enable versatile operation for industrial inspection and exploration.
• Electroadhesion provides a viable mechanism for micro-robots to overcome gravitational constraints in confined spaces.