May 6, 2024

These Tiny Liquid Robots Never Run Out of Energy As Long as They Have Food

For many years, scientists have desired to make a robot that can work autonomously and continually, without electrical input.

Now, as reported recently in the journal Nature Chemistry, scientists at the Department of Energys Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of Massachusetts Amherst have actually demonstrated just that– through “water-walking” liquid robots that, like small submarines, dive listed below water to obtain precious chemicals, and after that surface to deliver chemicals “ashore” once again and again.
In this short video, liquid robotics just 2 millimeters in diameter transport chemicals backward and forward while partly submerged in service. Credit: Ganhua Xie and Tom Russell/Berkeley Lab
The technology is the first self-powered, aqueous robot that runs continuously without electrical power. It has prospective as an automated chemical synthesis or drug delivery system for pharmaceuticals.
” We have broken a barrier in designing a liquid robotic system that can operate autonomously by utilizing chemistry to control an objects buoyancy,” stated senior author Tom Russell, a visiting faculty scientist and teacher of polymer science and engineering from the University of Massachusetts Amherst who leads the Adaptive Interfacial Assemblies Towards Structuring Liquids program in Berkeley Labs Materials Sciences Division.
Russell stated that the technology considerably advances a household of robotic gadgets called “liquibots.” In previous research studies, other scientists demonstrated liquibots that autonomously carry out a job, however just as soon as; and some liquibots can perform a job constantly, however require electrical power to keep running. In contrast, “we dont have to provide electrical energy because our liquibots get their power or food chemically from the surrounding media,” Russell discussed.
Through a series of experiments in Berkeley Labs Materials Sciences Division, Russell and very first author Ganhua Xie, a previous postdoctoral researcher at Berkeley Lab who is now a teacher at Hunan University in China, found out that “feeding” the liquibots salt makes the liquibots much heavier or denser than the liquid service surrounding them.
Extra experiments by co-investigators Paul Ashby and Brett Helms at Berkeley Labs Molecular Foundry exposed how the liquibots transport chemicals backward and forward.
Due to the fact that they are denser than the solution, the liquibots– which look like little bit open sacks, and are just 2 millimeters in size– cluster in the middle of the solution where they fill with choose chemicals. This activates a response that produces oxygen bubbles, which like little balloons raise the liquibot up to the surface area.
Another response pulls the liquibots to the rim of a container, where they “land” and unload their cargo.
The liquibots go back and forth, like the pendulum of a clock, and can run continuously as long as there is “food” in the system.
Depending on their formulation, an array of liquibots could perform different jobs simultaneously. For example, some liquibots could discover various kinds of gas in the environment, while others react to specific types of chemicals. The innovation might also make it possible for self-governing, continuous robotic systems that evaluate little chemical samples for scientific applications, or drug discovery and drug synthesis applications.
Russell and Xie next strategy to investigate how to scale up the innovation for bigger systems, and check out how it would work on strong surface areas.
Recommendation: “Continuous, autonomous subsurface cargo shuttling by nature-inspired meniscus-climbing systems” by Ganhua Xie, Pei Li, Paul Y. Kim, Pei-Yang Gu, Brett A. Helms, Paul D. Ashby, Lei Jiang and Thomas P. Russell, 29 November 2021, Nature Chemistry.DOI: 10.1038/ s41557-021-00837-5.
The Molecular Foundry is a nanoscience user center at Berkeley Lab.
This work was supported by the DOE Office of Science. Additional assistance was provided by the U.S. Army Research Office.

In previous research studies, other researchers demonstrated liquibots that autonomously carry out a job, but simply as soon as; and some liquibots can carry out a task continuously, but require electrical energy to keep on running. In contrast, “we do not have to offer electrical energy due to the fact that our liquibots get their power or food chemically from the surrounding media,” Russell discussed.
Depending on their formulation, a range of liquibots could bring out different jobs simultaneously. Some liquibots could identify various types of gas in the environment, while others react to specific types of chemicals.

Artists rendering of self-governing, constant “liquid robots” in an animated GIF. Credit: Jenny Nuss/Berkeley Lab
By eliminating electricity from formula, discovery conquers yearslong obstacle in robotics.
When you think about a robotic, images of R2-D2 or C-3PO may enter your mind. However robotics can provide more than simply entertainment on the huge screen. In a laboratory, for example, robotic systems can enhance safety and performance by carrying out repeated jobs and handling severe chemicals.
Before a robotic can get to work, it requires energy– typically from electrical power or a battery. Even the most advanced robotic can run out of juice. For several years, researchers have wanted to make a robot that can work autonomously and constantly, without electrical input.