Researchers at the Max Planck Institute for Intelligent Systems, the Institute for Bioengineering of Catalonia (IBEC) and the University of Stuttgart have revealed in an article in Nature Communications that micromotors can be guided using tiny topographical patterns on the surfaces over which they swim.
Samuel Sánchez and Mykola Tasinkevych's ‘microswimmers’ are usually guided through fluids using specially engineered magnetic multilayer coatings, which combined with external magnetic fields, helps to control their trajectory.
An active particle approaches a micro-fabricated step and orients along it due to chemical activity and hydrodynamic interactions.
MPI for Intelligent Systems, Stuttgart
This new study, the result of a collaboration between experimental research and theory, demonstrates that the particles can use the features of the surfaces over which they swim to change their direction of motion.
“Micromotors tend to settle and move near surfaces, and we’ve seen that this tends to interfere with their swimming behaviour,” says group leader and ICREA research professor Samuel, who heads the Smart Nano-Bio-Devices group at IBEC and Stuttgart’s MPI-IS. “This led us to explore new methods to guide micromotors using surface alterations.”
Using a microfabrication process, the researchers modified surfaces to create a series of indentations or steps, several times smaller than the radius of the particle, which a specific type of micromotors – Janus particles, whose surfaces have two or more distinct physical properties – can use as signals to follow a particular path. This strategy is inspired by the one used by molecular motors in natural systems, where inside the cell, motor proteins bind to the cytoskeleton filaments to achieve directional motion.
The Janus particles are prepared by coating half of a silica particle with platinum. While the platinum face acts as a catalyst in hydrogen peroxide, the silica side remains inert, an asymmetry in chemical properties that leads to a self-propelled motion of these colloids.
The researchers noticed that the particles tend to have a stable orientation parallel to the surface, and exploited this phenomenon to guide the particles along sub-micron sized steps. They were able to demonstrate that the chemical activity of the particles and the associated hydrodynamic interactions with the nearby surfaces are responsible for the observed phenomenon.
“This finding opens up the possibility of guiding these particles along complex pathways using small changes in the surface,” explains Samuel. “This can have significant implications for the design of new artificial micromotors for a variety of applications.”
Simmchen, J., Katuri, J., Uspal, W.E., Popescu, M.N., Tasinkevych, M., and Sanchez, S. (2016). Sculpted topographical pathways guide chemical microswimmers. Nature Communications Volume: 7, Article number: 10598, DOI:10.1038/ncomms10598
Annette Stumpf | Max-Planck-Institut für Intelligente Systeme
‘Farming’ bacteria to boost growth in the oceans
24.10.2016 | Max-Planck-Institut für marine Mikrobiologie
Calcium Induces Chronic Lung Infections
24.10.2016 | Universität Basel
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
24.10.2016 | Earth Sciences
24.10.2016 | Life Sciences
24.10.2016 | Physics and Astronomy