Tag Archives: Rotibot: Use of Rotifers as Self‐Propelling Biohybrid Microcleaners

Biohybrid cyborgs

Cyborgs are usually thought of as people who’ve been enhanced with some sort of technology, In contemporary real life that technology might be a pacemaker or hip replacement but in science fiction it’s technology such as artificial retinas (for example) that expands the range of visible light for an enhanced human.

Rarely does the topic of a microscopic life form come up in discussion about cyborgs and yet, that’s exactly what an April 3, 2019 Nanowerk spotlight article by Michael Berger describes in relationship to its use in water remediation efforts (Note: links have been removed),

Researchers often use living systems as inspiration for the design and engineering of micro- and nanoscale propulsion systems, actuators, sensors, and robots. …

“Although microrobots have recently proved successful for remediating decontaminated water at the laboratory scale, the major challenge in the field is to scale up these applications to actual environmental settings,” Professor Joseph Wang, Chair of Nanoengineering and Director, Center of Wearable Sensors at the University California San Diego, tells Nanowerk. “In order to do this, we need to overcome the toxicity of their chemical fuels, the short time span of biocompatible magnesium-based micromotors and the small domain operation of externally actuated microrobots.”

In their recent work on self-propelled biohybrid microrobots, Wang and his team were inspired by recent developments of biohybrid cyborgs that integrate self-propelling bacteria with functionalized synthetic nanostructures to transport materials.

“These tiny cyborgs are incredibly efficient for transport materials, but the limitation that we observed is that they do not provide large-scale fluid mixing,” notes Wang. ” We wanted to combine the best properties of both worlds. So, we searched for the best candidate to create a more robust biohybrid for mixing and we decided on using rotifers (Brachionus) as the engine of the cyborg.”

These marine microorganisms, which measure between 100 and 300 micrometers, are amazing creatures as they already possess sensing ability, energetic autonomy, and provide large-scale fluid mixing capability. They are also are very resilient and can survive in very harsh environments and even are one of the few organisms that have survived via asexual reproduction.

“Taking inspiration from the science fiction concept of a cybernetic organism, or cyborg – where an organism has enhanced abilities due to the integration of some artificial component – we developed a self-propelled biohybrid microrobot, that we named rotibot, employing rotifers as their engine,” says Fernando Soto, first author of a paper on this work (Advanced Functional Materials, “Rotibot: Use of Rotifers as Self-Propelling Biohybrid Microcleaners”).

This is the first demonstration of a biohybrid cyborg used for the removal and degradation of pollutants from solution. The technical breakthrough that allowed the team to achieve this task is based on a novel fabrication mechanism based on the selective accumulation of functionalized microbeads in the microorganism’s mouth: The rotifer serves not only as a transport vessel for active material or cargo but also acting as a powerful biological pump, as it creates fluid flows directed towards its mouth

Nanowerk has made this video demonstrating a rotifer available along with a description,

“The rotibot is a rotifer (a marine microorganism) that has plastic microbeads attached to the mouth, which are functionalized with pollutant-degrading enzymes. This video illustrates a free swimming rotibot mixing tracer particles in solution. “

Here’s a link to and a citation for the paper,

Rotibot: Use of Rotifers as Self‐Propelling Biohybrid Microcleaners by Fernando Soto, Miguel Angel Lopez‐Ramirez, Itthipon Jeerapan, Berta Esteban‐Fernandez de Avila, Rupesh, Kumar Mishra, Xiaolong Lu, Ingrid Chai, Chuanrui Chen, Daniel Kupor. Advanced Functional Materials DOI: https://doi.org/10.1002/adfm.201900658 First published: 28 March 2019

This paper is behind a paywall.

Berger’s April 3, 2019 Nanowerk spotlight article includes some useful images if you are interested in figuring out how these rotibots function.