Electric-field-guided precision manipulation of catalytic nanomotors

Significance 

The field of micro and nanomachines have been explored and rapidly advanced over the past decades. It includes components such as micromotors and nanomotors which have found numerous applications in nanofactories and nanorobots. As a result, they have helped revolutionize industries in the modern industries and hence changing lives in one way or the other.

Their function however can be fully realized when the integration of the autonomous components of such machines is done properly with the required accuracy and precision. This will ensure that the nanomachines are even capable of powering themselves with minimal human input thereby enhancing automation. Presently, nanomotors have been developed with various improvements that enable them to harness energy from external fields or chemical reactions and use it in propelling themselves.

Catalytic nanomotors which represent a sub-classification of the autonomous nanomotors can be used for efficient conversion of chemical energy into other forms of energy such as mechanical energy. Since catalytic nanomotors can be used in a variety of industrial applications such as drug delivery, cargo transport, and biochemical sensing among others, various manipulations approaches have been used in an attempt to realize their full functionality in the various applications.

Despite their excellent performances, there is still need to improve further their functionality regarding propulsion speed and high precision alignments. For instance, high accuracy and speed tuning in such motors have remained a challenge for some of the available manipulation techniques such as using magnetic fields acoustic tweezers and catalytic reactivities.

A group of researchers from The University of Texas, Department of Mechanical Engineering in the United States: PhD student Jianhe Guo, Jeremie June Gallegos, Ashley Robyn Tom, and Professor Donglei Fan reported an effective method for catalytic nanomotors manipulation with high precision, accuracy, and facileness. Their work is currently published in the journal, ACS Nano.

In their work, they used a combination of AC and DC electromagnetic fields consolidated in a 3-dimensional perpendicular microelectrode setup. The systems used the effects of electrophoretic and electroosmosis formed in the DC E-field for controlling the speeds while the help of the AC E-fields achieved the alignment of the nanomotors. Generally, it is a two-step method for demonstrating the manipulation of the nanomotors, that is, the dynamic loading and unloading of the micro targets and the integration of the catalytic nanomotors together with the nanomechanical devices.

The research team successfully affirmed the linear relationship between the size and speed of the catalytic nanomotors. The similarities of their results to the theoretical ones that were published in the previous research work proved further the accuracy of the experiment.

The manipulation method supported the various nanomotors applications such as the cargo capture, transport, and delivery to the required destination. It also enabled assembling of catalytic nanomotors for use as powering devices in nanomechanical devices. This work would, therefore, advance the design and manufacturing of various machines for various industrial applications such as the nanorobots. The versatility of this method can also see such machines used in other fields such as medical research.

About the author

Jianhe Guo is a Ph.D. candidate in the materials science and engineering program at the University of Texas at Austin. He received his bachelor’s degree in materials chemistry from the University of Science and Technology of China (USTC) in 2012. He holds HHMI International Student Research Fellowship. His research focuses on the design and manufacturing of innovative nanomotors, and their applications in microfluidics and biomedicines.

About the author

Donglei Fan is an Associate Professor in the Department of Mechanical Engineering at The University of Texas at Austin. She holds the Robert & Jane Mitchell Endowed Faculty Fellowship in Engineering. Her research focuses on exploiting the fundamental magnetic, optical, chemical, and mechanical properties of materials for innovative design, manufacturing, and applications of nanomaterials in nanorobotics, biochemical sensing, single live-cell stimulation, MEMS/NEMS, and energy conversion and storage devices.

Reference

Guo, J., Gallegos, J., Tom, A., & Fan, D. (2018). Electric-Field-Guided Precision Manipulation of Catalytic Nanomotors for Cargo Delivery and Powering Nanoelectromechanical Devices. ACS Nano, 12(2), 1179-1187..

Go To ACS Nano

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