Multi-Material Milli-Robot Prototyping Process
S. Bergbreiter, J. Rajkowski
This project is sponsored by NSF and the Minta Martin Fund.
Microrobotics, Prototyping, SMA, UV-curable Polymers
Interest in fabricating large numbers of small robots has grown recently due to applications ranging from mobile sensor networks to search and rescue. However, realizing these applications is difficult due to the extended fabrication time, cost, and fragility of current robot manufacture and design. Several mobile robots have been demonstrated at the centimeter-scale, but they generally lack robustness and cannot be easily manufactured in large numbers. These robots also require high one-time equipment costs and can take a day or more to assemble.
The process outlined in this work uses inexpensive, compliant photo-patternable materials with the ability to embed components to combine the benefits of small-scale robots with the robustness and compliance improvements in larger-scale robots. Compliant mechanisms will improve the mobility and robustness of robots on the centimeter and millimeter-scales and can also be used to add mechanical energy storage for improved efficiency. Finally, the use of these polymers will allow many milli-robots to be fabricated in less than an hour on a benchtop instead of several weeks in a clean room or after many hours of assembly. While this process is currently limited to planar structures, separately constructed components can be stacked and folded to create more complex robots.
The objectives of this project are:
1. Development of a fabrication process that incorporates multiple UV-curable polymers with different material properties to create complex robot mechanisms.
2. Reduce feature sizes below 100 microns.
3. Robust integration of efficient actuators with robot mechanisms.
4. Test new locomotion methods to better study and understand efficient and effective locomotion at the sub-cm scale.
Overview of approach
The milli robot prototyping process is described in the figure and video below. In addition, several mobile robots have already been fabricated and tested in this process.
Process steps for the multi-material prototyping process. The
different color components represent materials with different material
properties—green represents a more rigid polymer and the blue is a
soft, flexible silicone. These polymers are patterned using a
photolithography process with the masks in steps 3 and 6.
Rajkowski, J.E., Gerratt, A.P., Schaler, E.W., and Bergbreiter, S. “A Multi-Material Milli-Robot Prototyping Process,” IROS 2009, St. Louis, October 11-15, 2009.
Dr. Sarah Bergbreiter
Department of Mechanical Engineering and Institute for Systems Research
2170 Martin Hall
University of Maryland
College Park, MD-20742