Engineers Edge –- Engineers and physicians at the University of Pennsylvania have developed a carbon nano-pipe thousands of times thinner than a human hair that can deliver fluids into growing cells and measure electric current. The tiny carbon-based tool can be used to probe cells with minimal intrusion and inject fluids without damaging or inhibiting cell growth.

Glass micro-pipes are used within most cell laboratory in the world, but are fragile and easily broken and can cause irreparable cell damage. Additionally, current micro-pipe technology cannot be used as injectors and electrodes. Haim Bau, a professor in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania, and his team developed tiny carbon-based pipettes that can be mass-produced to eliminate the problems associated with glass micropipettes. The developed nano-pipes range in size from approximately 3 to a 300 nanometers and are stronger and more flexible than traditional glass micro-pipes.

Researchers project that the nano-pipes will be used to measure electrical signals of cells during fluid injection activities. Additionally, the nano-pipes are not visiable to X-rays and electrons, allowing imaging even at the molecular level. When a fictionalized protein is included with the nano-pipe a nanoscale biosensor is created that can be used to detect the presence of proteins.

“University of Pennsylvania Micro-Nano Fluidics Laboratory now mass-produces these pipettes and uses them to inject reagents into cells without damaging the cells,” Bau said. "We are ultimately interested in developing nanosurgery tools to monitor cellular processes and control or alter cellular functions. We feel CNPs will help scientists gain a better understanding of how a cell functions and help develop new drugs and therapeutics."

Of equal importance as the mechanical properties of carbon nano-pipes, is the manufacturability, said Michael Schrlau. Nano-pipes are manufactured by depositing a carbon film inside quartz micro-pipe, then wet-etch away the quartz tip to expose a carbon nanopipe. Michael Schrlau indicates that they can simultaneously produce hundreds of these integrated nanoscale devices.