/Self-Propelled Nanomotor
Nanomotors in nature, the tail of a bacterium. © BBC

Self-Propelled Nanomotor

“Be faithful in small things because it is in them that your strength lies.” – Mother Teresa

This inspirational quote sometimes can be related to the scientific world as well. The world is evolving with new exploration day by day and transform itself from micro to nano regime and scientists were having faith in these small things. Nanotechnology has become a very exciting for research and development as it presents a tremendous potential to a variety of applications. In the hierarchy of age’s right from Stone Age, Bronze Age, Iron Age, Silicon Age and what we can expect next? Nevertheless, to say, we are very in nanotech age, where materials are just getting smaller day-by-day!  The word nano is defined as a unit of a billionth, derived from the ancient Greek word nanos, meaning pigmy (dwarf). The length of 1 nanometer (nm) is 10-9 m, which is about 1/80,000 of the thickness of a hair. According to National Nanotechnology Initiative (NNI) situated in the United States, nanotechnology is a blend of science, engineering, and technology which has a range of 1-100 nm (nanometer) with a large surface to volume ratio. The reason that scientists and engineers are attracted to this nanoworld is due to its size related properties. It shows intermediate properties of both molecular structure as well as of bulk materials (larger materials) because of its smaller size and that too without changing the chemical status of the particular material. Also, these nanomaterials are light-weighted, have high strength, and are more chemically reactive and electrical conductivity as compared to bulk materials. There are many innovative ideas associated with Nanotechnology. One of these is self-propellent nanomotors.

Got a Scratched Gadget? Self-Propelled Nanomotors to the Rescue

Have you ever wonder if somehow our gadget can heal their wounds after a crack? Yes, thanks to tiny, self-propelled nanomotors that can detect the damage and repair it by itself. If these scratches occur in electrical circuits, it can hinder the current flow and can disturb the performance of the device. Self-propelled nanomotors are actually inspired by biological self-healing systems, where the nanomotors can effectively seek and locate defects and thus enable in situ repair. Engineers from the University of California, San Diego and the University of Pittsburgh have designed nanomotors which are the nanoscale devices that can convert energy into movements. They can detect and move toward these scratches before wedging themselves into the cracks. They are basically made from gold and platinum that conduct electricity and act as a bridge in the gap as shown in Figure below.


Self-Propelled Nanomotors Autonomously Seek and Repair Cracks
(A) The structure of the functionalized Au/Pt spherical nanomotor. (B, C) Self-propelled nanoparticles could rush to the scene of a scrape in an electronic and bridge the gap to complete the circuit again lighting up the bulb. © Author: Jinxing Li et al., Journal: pubs.acs.org/NanoLett, DOI: 10.1021/acs.nanolett.5b03140

To build the nanomotors, the researchers first created tiny gold spheres and coated one-half of each sphere with platinum, which acts as a catalyst to break down the fuel that propels them [Fig.1(a)]. The nanomotors self-propel of bimetallic Au/Pt catalyst are applied in a liquid solution that also contains the hydrogen peroxide fuel that powers them. The cracks in electrical circuits are typically hydrophobic, so, the particles were made hydrophobic by functionalizing the surface of the gold hemisphere of the nanomotors with a self-assembled monolayer of octadecanethiol (Fig 1. (A) light blue color). These alkenethiol hydrophobic monolayers enhance the motor interaction with the exposed hydrophobic cracks. Therefore, the researchers were able to nudge the particles to naturally seek out scratches. The tiny particles are also drawn to other nanomotors, thus allowing them to form clusters that can bridge larger gaps in a circuit. These healed circuits will lead to enhanced device reliability and increased longevity in adverse mechanical environments, enabling new applications in microelectronics, advanced batteries, and electrical systems. This self-propelled nanomotor concept can be extended to repair the biological, mechanical, optical, or electronic properties of a wide range of damaged materials. The use of self-propelled nanomotors opens the door for artificial responsive nanosystems with advanced biomimetic functionalities for a wide variety of applications ranging from self-healing nanodevices to targeted drug delivery.

    All the videos and pictures are taken from the original article:

  • Author: Jinxing Li et al.
  • Journal: pubs.acs.org/NanoLett
  • DOI: 10.1021/acs.nanolett.5b03140
  • Featured Image: Nanomotors in nature, the tail of a bacterium. © BBC


Cite this article as: Liza Sarma, Author, "Self-Propelled Nanomotor," in Good Morning Science, April 20, 2017, https://gmsciencein.com/2017/04/20/self-propelled-nanomotor/.

The author is pursuing Ph.D. in the field of ‘Nanotechnology and its various applications’ from the University of Delhi with CSIR JRF. She holds an M.Tech. degree from Indian Institute Of Technology Delhi (IITD) with a project entitled ‘Synthesis and characterization of transition metal doped transparent conducting CuAlO2 oxide nanoparticles’. Prior to enrolling at IITD, she pursued M.Sc. and B.Sc. degree from Dibrugarh University (Assam).
Apart from Academics, she received Visharad in Bharatnatyam and perform dance in various platforms.