I’ve mentioned a few times various projects that aim to help clean up our oceans and waterways. For instance, the Row-Bot, from a team in Bristol, feeds on pollution in the water, with the nutrients used to power the robot onto its next ‘meal’.
I also mentioned the floating barriers developed as part of the Ocean Cleanup project, which consists of a number of v-shaped floating barriers that are attached to the sea floor. As the current washes plastic through the barriers, they are caught up in the device, which then concentrates the plastic via a non-permeable screen that sits beneath the surface.
Release the microbots
Another fascinating attempt at using technology was described in a recent paper that described the use of microbots that are capable of literally absorbing lead and other pollutants from water.
“This work is a step toward the development of smart remediation system where we can target and remove traces of pollutant without producing an additional contamination,” the authors say.
Whilst the projects mentioned earlier focused on things like plastic, this one was going after heavier pollution that results from industrial activity. We’re talking the kind that leads to lead, mercury, arsenic and the like finding their way into our water.
The microbots were tube-shaped constructions consisting of three layers. The outer layer absorbed the lead from the water using graphene oxide. The bots are controlled by the middle layer, where nickel creates a ferromagnetic force that directs the motion of the robots. The inner layer provides the propulsion for the bots via a platinum propulsion system that feeds off of the hydrogen in the water.
Once the bots have finished harvesting the lead from the water, they can be scooped up by using a magnetic field, before an acidic solution is then applied to strip the lead ions from them so that they can be re-used elsewhere.
“This is a new application of smart nanodevices for environmental applications,” the researchers say. “The use of self-powered nanomachines that can capture heavy metals from contaminated solutions, transport them to desired places and even release them for ‘closing the loop’—that is a proof-of-concept towards industrial applications.”
The team believe that the bots could eventually be controlled automatically as magnetic fields guide them towards certain tasks. They also believe they can be used for other pollutants too.
“We plan to extend the microbots to other contaminants, and also importantly reduce the fabrication costs and mass-produce them,” they say.
It’s certainly a fascinating technology with a very worthwhile goal. Certainly one to keep an eye on.