Project 6

characterization of microrobots inside the scanning electron microscope

(Prof. dan POPA, ECE)

Over the last few years, the Next Generation Systems (NGS) research group at University of Louisville has been prototyping novel 3-dimensional microrobots designed for future manipulation tasks in dry environments. An example of such microrobots is the Solid Articulated Four Axes Microrobot (sAFAM – Figure 1 left), designed and fabricated in our cleanroom based on Microelectromechanical System (MEMS) technology, then assembled to achieve out-of-plane motion and perform micro manipulation tasks such as carbon nanotube pick and place. Four conventional in-plane thermal actuators drive the end-effector of sAFAM through complaint mechanical coupling. The proposed structure was simulated by finite element analysis (FEA) and validated experimentally, resulting in an 20um x 50um x 200um workspace, 10 nm resolution, and 40 nm repeatability measured using a Keyence Interferometric sensor. The sAFAM is thus an example of a miniature “fixed” manipulator arm in the microfactory. A second microrobot is the ChevBot (Figure 1 right), a novel untethered microrobot that operates using stick and slip actuation, powered by a 1W Nd:YAG pulsed laser beam delivered onto the robot. The ChevBot has dimensions of approximately 500um x 300um x 40um, and can achieve speeds in excess of 50 microns per second when illuminated with pulsed laser frequencies between 5 and 50 kHz The ChevBot is an example of a miniature “mobile” microrobot for the microfactory, and can be used to transport nanoparts. In this project, students will be evaluating the performance of sAFAM and ChevBot inside a SUPRA 35 SEM at UofL’s Micro and Nano Technology Center. Performance metrics includes positional accuracy, cycle time, and yield of assembly operations with nanotubes, nanospheres, and other miniature objects.