A swarm of tiny machines, speeding in concert through the bloodstream to repair an organ or deliver a drug to its target area, microrobots working together to construct a nanotechnological component—although it sounds like science fiction, it is a thoroughly realistic future scenario.
Amazing progress has already been made in the production of autonomous nano- and micromotors, but the little machines have continued to lack in team spirit. To complete challenging tasks, the individual machines must communicate and cooperate with each other.
Researchers led by Ayusman Sen at Pennsylvania State University (USA) have now introduced silver chloride microparticles that can “swarm” together, almost like living single-celled organisms. As reported in the journal Angewandte Chemie, irradiation with UV light causes the particles to give off “signal substances” that “attract” other particles.
Living cells and organisms are able to exchange information with each other to accomplish tasks as a team. Single-celled slime molds, for example, living in unfavorable conditions thus release a special substance. Neighboring slime molds follow the gradient of this signal substance and aggregate in the form of a multi-celled fruiting body. The silver chloride particles used by Sen’s team, which are about 1µm in size, behave in a similar fashion when irradiated with UV light. Silver chloride decomposes under UV light, releasing ions that act as both a propulsion mechanism and signal substance.
This phenomenon is based on diffusiophoresis, the movement of particles along an electrolyte gradient. The silver chloride particles “swim” toward a higher ion concentration. Because of irregularities in the surfaces of the particles and non-uniform irradiation, the degradation of the particles is asymmetric. Different quantities of ions are released in different places on the surface, which results in a local ion gradient around the particles. The particle thus produces its own ion gradient, which propels it at speeds up to 100 µm/s (self-diffusiophoresis). Neighboring sliver chloride particles follow the ion gradient of the solution and “swim” to regions of higher particle density. After several minutes, this results in small, stable “swarms” of particles. Photochemically inactive silicon dioxide particles also react to the ion signal, aggregating around the silver chloride particles.
This system can be used as a nonbiological model for communication between cells. Most importantly though, it represents a new design principle for “intelligent” synthetic nano- or micromachines that can work together as a team.
Author: Ayusman Sen, The Pennsylvania State University, University Park (USA), http://research.chem.psu.edu/axsgroup/dr_sen.html
Title: Schooling Behavior of Light-Powered Autonomous Micromotors in Water
Angewandte Chemie International Edition 2009, 48, No. 18, 3308–3312, doi: 10.1002/anie.200804704
Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo
Research reveals how order first appears in liquid crystals
23.05.2018 | Brown University
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy