Autonomous Jumping Microrobots


Why Microrobots?

For me, mobile autonomous microrobots are defined as millimeter-sized mobile robots with power and control on board. These robots offer numerous advantages due to their size and low power requirements. For example, millimeter-sized microrobots could be used to add mobility to sensors in large-scale sensor networks as the size of those integrated sensors shrink as shown in the Berkeley Smart Dust Project. As end users are beginning to deploy large scale sensor networks for the first time, they are also beginning to discover how useful added mobility can be. In the example of a network designed to study some phenomenon in nature, scientists often need to redeploy a network based on information gathered from it (an animal spends most of its time in locations X and Y only). The same ideas apply in a defense related application. In addition, users may want sensors to move to locations other than where they were first deployed to fill gaps in the network or cover obscured or hard to reach areas. Large numbers of autonomous mobile microrobots could also be used for search in unstructured environments, surveillance, and micro construction tasks (termites).

Why Jumping?

At the millimeter size scale, jumping can offer numerous advantages for efficient locomotion, including dealing with obstacles and potentially latching onto larger mobile hosts (larger robots, animals, vehicles, etc). The design for an effective jumping microrobot is divided into four primary areas: energy storage, actuation, power, and control. Like its biological inspiration, the flea, a jumping microrobot requires an energy storage system to store energy and release it quickly to jump. Silicone micro rubber bands have been fabricated and assembled into the microrobot for this task. To stretch these micro rubber bands, electrostatic inchworm motors are chosen as actuators due to their high forces, long throw, and low input power requirements. Finally, solar cells and a microcontroller have been chosen to power and control the microrobot.

Publications

Bergbreiter, S.; Pister, K.S.J. "Design of an Autonomous Jumping Microrobot," ICRA 2007, Rome, April 10-14, 2007. (paper pdf) (presentation ppt)

Bergbreiter, S.; Pister, K.S.J. “An Elastomer-Based Micromechanical Energy Storage System,” ASME 2006, Chicago, IL, November 5-9, 2006. (paper pdf) (presentation ppt)

Movies

Demonstrating the quick release capabilities of the energy storage system. The leg is first held in place by large electrostatic clamps before release and shot an 0402-sized capacitor ~1.5cm along a glass slide.
Inchworm motor pulling an assembled micro rubber band. Watch the parallel flexures on each side to see the 30um of motion. Approximately 5nJ of energy is stored and released.

Walking/Crawling Microrobots

More information on walking microrobots previously designed in our lab can be found here

Sarah Bergbreiter
497 Cory Hall
UC Berkeley
Berkeley, CA 94720
sbergbre at eecs.berkeley.edu