Thursday, April 16, 2009

NanoRobotics Laboratory @ Carnegie Mellon University = (CMU: It's not just for people like Ethan Hawke, Josh Grobin, Holly Hunter, Jeff Daniels, etc.)

A robot that can run on the surface of water.
Goal: : Developing a robot which can run across the surface of water in a fashion similar to the Basiliscus basiliscus and other water-running lizards.

Approach: First, mathematical models of the lizard's interaction with the water are used to develop similar models for robot bodies and legs. A simple four bar mechanism has been adopted as the robot's propulsive mechanism. Proof-of-concept systems and supported prototypes are constructed to confirm and improve the mathematical models. Scale prototypes are constructed, and their lift and forward thrust abilities are measured. Through several iterations, improvements to the system are affected, and the overall system design may diverge (in appearance) from nature.

Benefits: Lizards that run across the surface of the water do not have to deal with the negative effects of viscous drag, like most swimming animals and boats. A robot that moves in a similar manner may be a more efficient way to travel across the water. Also, we wish to increase our understanding and extend the abilities of legged robots.

Current Status: Water running robots with on board and off-board power have been built which are capable of running across open water in outdoor environments. Work is being done to construct control and steering systems for more autonomous, untethered robots. New designs with higher degrees of freedom are being prototyped to allow for steering while water running. Amphibious designs are being researched.

Video 1: High speed video of water runner in small pool - 2007
Video 2: Water runner with off board power in small pool - 2007
Video 3: Water runner with on board power running on open water - 2007

Members: Steven Floyd, Hyun Soo Park, Metin Sitti Former Members: Terence Keegan, John Palmisano,

C. Menon, M. Murphy, M. Sitti, "Gecko Inspired Surface Climbing Robots" IEEE International Conference on Robotics and Biomimetics (ROBIO), Shenyang, China, Aug 2004. pdf-->In the News: Discovery Channel Article.Pittsburgh Live.

Water Strider Robot
A miniature water strider robot

BioInspired Adhesives
Gecko Hair Manufacture:
Synthetic Gecko Hair Fabrication for Dry Adhesives

Introduction: Nature can be an inspiration for innovations in science. One such inspiration is comes from the gecko lizard which can climb on walls and ceilings of almost any suface texture. Rather than using it's claws or sticky substances, the gecko is able to stick to smooth surfaces through dry adhesion which requires no energy to hold it to the surface and leaves no residue. The dry adhesion force comes from surface contact forces such as van der Waals forces which act between all materials in contact.
The gecko's trick to sticking to surfaces lies in its feet, specifically the very fine hairs on its toes. There are billions of these tiny hairs which make contact with the surface and create a huge collective surface area of contact. The hairs have physical propeties which let them bend and conform to a wide variety of surface roughnesses, meaning that the gecko's secret lies in the structure of these hairs themselves. By studying this structure, we are able to mimic the biological structures with synthetic materials.
The structure of the biological gecko hair is very complicated as well as very miniscule. Each hair is made from multiple sections, a micro-hair which is roughly 5 microns in diameter, and atop each of these micro-hairs sit tens to hundreds of nano-hairs which are 200 nanometers in diameter (1/250th of a human hair) in a tree-like branching structure.

Goal: Develop techniques for producing synthetic gecko foot hairs with nano/micro hair heirarchy. Refine these techniques into processes which will alow for cost effective mass production. Utilize the gecko hair material to create advanced ultra-mobile robots.
Approach: Our lab uses a multitude of techniques to produce the gecko hairs. The major areas of research are:
Directional Adhesives
Hierarchical Adhesives
Micro- and sub-micron size structures Micro and Nano Molding
MEMS Photolithography-->

By using our Force Characterization Systems we are able to get immediate feedback from our gecko hair samples, therefore we can rapidly evolve our designs to reach an optimal design. Benefits: The new synthetic adhesive will have countless uses from space exploration robots to surgical applications to post-it notes. This reusable, self-cleaning adhesive material can be thought of as a one sided velcro which can stick to almost everything.
Wall Climbing Robots

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

Telenano - Human AFM interface
Augmented Reality User Interface for Atomic Force Microscopes (AFM)

Goal: To develop a human-machine interface for atomic force microscope (AFM) based nano-scale manipulation. A haptic device lets the user control the position of the AFM-probe and relays measured forces to his fingertip. The user sees the topography of the nano-surface, including surface interactions, and probe positions in a realtime computer graphics environment.
Approach: An Omega 3-DOF haptic device is interfaced with an M5 Atomic Force Microscope through a control PC at high bandwidth. As imaging from the AFM is non-realtime, a virtual simulation is employed to estimate the nano-world, including modelling nano-scale deformations. The nano-surface is therefore represented by a spline, and the probe as a sphere. An efficient collision detection algorithm determines whenever the probe penetrates the surface and gives the geometry of contact.
Forces are determined from the cantilever deflections, measured from the AFM. As forces are coupled in the x and z directions from the direct AFM data, force modelling and the virtual environment are used to decouple and determine forces as a 3D vector.
Control strategies will be implemented to ensure stability of manipulation, and will be implemented for task-based guided nanomanipulation.
Models: Modelling the interaction of the probe and the surface. The interaction of the afm-probe and the surface is modelled in realtime 3D. The surface is therefore represented by a spline and the probe as a sphere. An efficient collision detection algorithm determines whenever the probe penetrates the surface and gives the geometry of the contact. Noncontact force models, continuum mechanics contact models (JKR and Maugis' JKR-DMT Transition) together with a simple rectangular beam model of the probe yield the interaction forces and deformations.

Benefits: With a 3D computer simulation coupled with realtime force feedback, an AFM can become a nanomanipulation tool where a user can interact with nano-size entities as easily as if they were lagre objects on the desk in front of them. This expands the utility of the AFM from simply a scanning device to a manufactuing tool with which one can assemble structures that are virtually impossible to build presently. Furthermore this system can allow novice users with little training to utilize the advanced capabilities of the system and become intuitively familiar with nano-scale physics.
Video 1: Low quality [1.9 MB]Video 1: High quality [7.2 MB]
Therapeutic Capsule Endoscopes: A new controllable device for minimally invasive interventions

Best of the Roses,
"John French"
John Alan Conte, Jr.

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