Robotic assembly of world’s smallest house
AFrench nanorobotics team from the Femto-st Institute in Besançon, France, assembled a new microrobotics system that pushes forward the frontiers of optical nanotechnologies.
Combining several existing technologies, the μrobotex nanofactory built microstructures in a large vacuum chamber and ¿xes components onto optical ¿ber tips with nanometer accuracy, phys.org wrote.
The microhouse construction, reported in the Journal of Vacuum Science and Technology A, demonstrates how researchers can advance optical sensing technologies when they manipulate ion guns, electron beams and ¿nely controlled robotic piloting.
Until now, lab-on-¿ber technologies had no robotic actuators for nanoassembly, so working at this scale inhibited engineers from building microstructures.
This innovation allows miniaturized sensing elements to be installed on ¿ber tips so engineers can see and manipulate different components.
With this advancement, optical ¿bers as thin as human hair can be inserted into inaccessible locations like jet engines and blood vessels to detect radiation levels or viral molecules.
Jean-yves Rauch, an author on the paper, said, “For the ¿rst time we were able to realize patterning and assembly with less than two nanometers of accuracy, which is a very important result for the robotics and optical community.”
The French engineers combined all the technological components for nanoassembly — a focused ion beam, a gas injection system and a tiny maneuverable robot — in a vacuum chamber, and installed a microscope to view the assembly process.
Rauch said, “We decided to build the microhouse on the ¿ber to show that we are able to realize these microsystem assemblies on top of an optical ¿ber with high accuracy.”
Building a microhouse is like making a giant dice from a piece of paper, but nanoassembly requires more sophisticated tools.
The focused ion beam is used like scissors to cut or score the silica membrane ‘paper’ of the house.
Once the walls fold into position, a lower power setting is selected on the ion gun, and the gas injection system sticks the edges of the structure into place.
The low-power ion beam and gas injection then gently sputters a tiled pattern on the roof, a detail that emphasizes the accuracy and Àexibility of the system.
In this process, the ion gun had to focus on an area only 300 micrometers by 300 micrometers to ¿re ions onto the ¿ber tip and silica membrane.
Rauch said, “It’s very challenging to pilot the robot with high accuracy at this cross point between the two beams.”
He explained that two engineers worked at multiple computers to control the process.
Many steps are already automated, but in the future the team hopes to automate all the robotic stages of assembly.
Now, using the μrobotex system, these engineers are constructing functionalized microstructures to detect speci¿c molecules by attaching their microstructures onto optical ¿bers.
The nanorobotics team is hoping to push the limits of the technology further still, by constructing smaller structures and ¿xing these onto carbon nanotubes, only 20 nanometers to 100 nanometers in diameter.