Home | Publications | Members | Contact | Projects | Publicity | Equipment

Robotic Micro-Assembly
Precise manipulation and autonomous assembly of micro and nano-sized structures.

To develop a robotic manipulation system that can autonomously construct complex three-dimensional micro and nano-structures from micro and nano-parts. To develop a large-scale assembly system to mass-assemble micro and nano-devices.

Using a 3-axis piezo-electric positioning stage with sub-micrometer to sub-nanometer precision, the control of an end-effector in a micro to nano-sized workspace is realized. Using an Optical Microscope as an imaging device for the micro-scale, or an Atomic Force Microscope as an imaging and manipulation device at the nano-scale, the workspace can be imaged. Vision processing can detect objects in the workspace; combined with high-level task planning, paths can be formulated to assemble the micro or nano-parts in a user-defined configuration.

The physical manipulation of objects can be realized by using nano-probes such as an AFM or STM tip as a two-dimensional manipulator. Three-dimensional manipulators including micro-fabricated grippers, laser trapping methods, and dielectrophoretic techniques can be implemented.

Current Status
A micromanipulation system is developed that can autonomously construct two-dimensional micro-arrangements of spheres sized from 3um to 20um in diameter. The assembly system consists of: (1) A nano-probe, (2) a three-axis piezo-electric stage (100x100x15um range in x,y,z) that is controlled digitally in a realtime operating system (RTAI Linux) and holds the nano-probe, (3) a three-axis coarse positioning stage that the sample is mounted to, (4) a high-powered optical microscope using a 50x objective (~500x zoom), and (5) a camera and frame-grabber allowing the workspace to be imaged, providing a sensory feedback for the control loop.

In the control, the user specifies a particle arrangement the manipulation system should achieve. Using the Hough transform, objects in the workspace are detected, and using a Wavefront expansion planner, paths are generated to attain the goal state. Finally the nano-probe is servoed on the path, pushing the particles, until the goal state is achieved.

Current efforts include extending the system into the nano-scale by investigating Atomic Force Microscopy as an imaging and manipulation device.

The development of certain micro and nano-devices, particularly complex three-dimensional structures such as micro-fabricated motors, are performed manually. This is not feasible for low-cost large-scale manufacture, however an autonomous assembly system can solve this problem. Complex micro and nano-devices will be more readily available and can be incorporated into more complicated systems.

Video 1: Pushing a 10um microsphere [5MB]
Video 2: Creating the letter M with microspheres [20MB]

Metin Sitti

Former Members
Cagdas Onal, Chytra Pawashe, Nicholas Lynch


  • N. A. Lynch, C. D. Onal, E. Schuster, and M. Sitti, "Vision-based feedback strategy for controlled pushing of microparticles," Journal of Micro/Nano-Mechatronics , 2008. pdf
  • N. A. Lynch, C. D. Onal, E. Schuster, and M. Sitti, "A Strategy for Vision-Based Controlled Pushing of Microparticles," IEEE International Conference on Robotics and Automation, 2007.
  • C. D. Onal and M. Sitti, "Autonomous 2D Microparticle Manipulation based on Visual Feedback," IEEE/ASME International Conf. on Advanced Intelligent Mechatronics, 2007.
  • C. D. Onal and M. Sitti, ''Visual Servoing Based Autonomous 2D Manipulation of Microparticles using a Nanoprobe,'' IEEE Trans. on Control Systems Technology, 2007, in press.
  • C. Pawashe and M. Sitti, ''Two-Dimensional Vision-Based Autonomous Microparticle Assembly using Nanoprobes,'' Journal of Micromechatronics, vol. 3, no. 3-5, pp. 285-306, 2006. pdf
  • A. Tafazzoli, C. Pawashe, and M. Sitti, ''Force-Controlled Microcontact Printing using Microassembled Particle Templates,'' Proc. of the IEEE Robotics and Automation Conference, pp. 263-268, Orlando, FL, May 2006. pdf
  • M. Sitti, ''Teleoperated and Automatic Control of Nanomanipulation Systems using Atomic Force Microscope Probes,'' Proc. of the IEEE Conf. on Decision and Control, Maui, Hawaii, Dec. 2003. (Invited Paper) pdf
  • M. Sitti and H. Hashimoto, ''Controlled pushing of nanoparticles: Modeling and experiments,'' IEEE/ASME Trans. on Mechatronics, vol. 5, no. 2, pp. 199-211, 2000. pdf

  • [Semi-autonomous assembly of CMU pattern using 10um spheres]
    [Micromanipulation system under optical microscope]
    [AFM nano-probe and 4.5um particles in the workspace]
    [Microgrippers Approaching a 10um Microsphere]