A DNA nanorobot is programmed to pick up and sort molecules into predefined regions.
Imagine a robot that could help you tidy your home: roving about, sorting stray socks into the laundry and dirty dishes into the dishwasher. While such a practical helper may still be the stuff of science fiction, Caltech scientists have developed an autonomous molecular machine that can perform similar tasks—at the nanoscale. This “robot,” made of a single strand of DNA, can autonomously “walk” around a surface, pick up certain molecules and drop them off in designated locations.
The work was done in the laboratory of Lulu Qian, assistant professor of bioengineering. It appears in a paper in the September 15 issue of Science.
Why Nanobots?
“Just like electromechanical robots are sent off to faraway places, like Mars, we would like to send molecular robots to minuscule places where humans can’t go, such as the bloodstream,” says Qian. “Our goal was to design and build a molecular robot that could perform a sophisticated nanomechanical task: cargo sorting.”
How to Build a Molecular Robot
Led by former graduate student Anupama Thubagere (PhD ’17), the researchers constructed three basic building blocks that could be used to assemble a DNA robot: a “leg” with two “feet” for walking, an “arm” and “hand” for picking up cargo, and a segment that can recognize a specific drop-off point and signal to the hand to release its cargo. Each of these components is made of just a few nucleotides within a single strand of DNA.
In principle, these modular building blocks could be assembled in many different ways to complete different tasks—a DNA robot with several hands and arms, for example, could be used to carry multiple molecules simultaneously.
In the work described in the Science paper, the Qian group built a robot that could explore a molecular surface, pick up two different molecules—a fluorescent yellow dye and a fluorescent pink dye—and then distribute them to two distinct regions on the surface. Using fluorescent molecules enabled the researchers to see if the molecules ended up in their intended locations. The robot successfully sorted six scattered molecules, three pink and three yellow, into their correct places in 24 hours. Adding more robots to the surface shortened the time it took to complete the task.
“Though we demonstrated a robot for this specific task, the same system design can be generalized to work with dozens of types of cargos at any arbitrary initial location on the surface,” says Thubagere. “One could also have multiple robots performing diverse sorting tasks in parallel.”
Design through DNA
The key to designing DNA machines is the fact that DNA has unique chemical and physical properties that are known and programmable. A single strand of DNA is made up of four different molecules called nucleotides—abbreviated A, G, C, and T—and arranged in a string called a sequence. These nucleotides bond in specific pairs: A with T, and G with C. When a single strand encounters a so-called reverse complementary strand—for example, CGATT and AATCG—the two strands zip together in the classic double helix shape.
A single strand containing the right nucleotides can force two partially zipped strands to unzip from each other. How quickly each zipping and unzipping event happens and how much energy it consumes can be estimated for any given DNA sequence, allowing researchers to control how fast the robot moves and how much energy it uses to perform a task. Additionally, the length of a single strand or two zipped strands can be calculated. Thus, the leg and foot of a DNA robot can be designed for a desired step size—in this case, 6 nanometers, which is about a hundred millionth of a human’s step size.
Using these chemical and physical principles, researchers can design not only robots but also “playgrounds,” such as molecular pegboards, to test them on. In the current work, the DNA robot moves around on a 58-nanometer-by-58-nanometer pegboard on which the pegs are made of single strands of DNA complementary to the robot’s leg and foot. The robot binds to a peg with its leg and one of its feet—the other foot floats freely. When random molecular fluctuations cause this free foot to encounter a nearby peg, it pulls the robot to the new peg and its other foot is freed. This process continues with the robot moving in a random direction at each step.
It may take a day for a robot to explore the entire board. Along the way, as the robot encounters cargo molecules tethered to pegs, it grabs them with its “hand” components and carries them around until it detects the signal of the drop-off point. The process is slow, but it allows for a very simple robot design that utilizes very little chemical energy.
Futuristic Applications
“We don’t develop DNA robots for any specific applications. Our lab focuses on discovering the engineering principles that enable the development of general-purpose DNA robots,” says Qian. “However, it is my hope that other researchers could use these principles for exciting applications, such as using a DNA robot for synthesizing a therapeutic chemical from its constituent parts in an artificial molecular factory, delivering a drug only when a specific signal is given in bloodstreams or cells, or sorting molecular components in trash for recycling.”
Learn more:: Sorting Molecules with DNA Robots
The Latest on: DNA robots
[google_news title=”” keyword=”DNA robots” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]- ECOVACS ROBOTICS Teams Up with New Brand Ambassador, South Korean Superstar Jun Ji-hyun, for a Dynamic Journey Aheadon April 29, 2024 at 7:51 pm
SINGAPORE - Media OutReach Newswire - 30 April 2024 - ECOVACS ROBOTICS, a global leader in service robotics, is thrilled to announce the appointment of Jun Ji-hyun, the celebrated South Korean actress ...
- Air Force marks key signpost in robot wingmen awardon April 29, 2024 at 4:44 pm
Anduril and General Atomics are well known in the defense industry. But their selections for phase one of the Collaborative Combat Aircraft program stand out for who they went up against and where the ...
- A.I. Start-Ups Face a Rough Financial Reality Checkon April 28, 2024 at 9:01 pm
The table stakes for small companies to compete with the likes of Microsoft and Google are in the billions of dollars. And even that may not be enough.
- The Weirdest Creatures In The Fallout Serieson April 28, 2024 at 10:30 am
It's true that throughout these adventures you'll run across many an odd enemy. Some are just humans who call the post-apocalyptic U.S. their home. Others though, are far more gruesome and far more ...
- DNA Exclusive: Looming Bomb Threat In West Bengal Amidst Lok Sabha Pollson April 27, 2024 at 11:02 am
In Todays DNA, Zee News analysed the current scenario of West Bengal which is currently receiving a threat from high-tech arms and bombs.
- Machine learning-powered robot streamlines genetic research processon April 26, 2024 at 9:26 pm
University of Minnesota Twin Cities researchers have constructed a robot that uses machine learning to fully automate a complicated microinjection process used in genetic research.
- The Long Comics History Behind X-Men's Sentinel Programon April 26, 2024 at 2:30 pm
For almost as long as they have been in the comics, the X-Men and mutantkind at large have been stalked by a world that hates and fears them—a world that manifested that hate in the metallic, ...
- Researchers Unveil Automated Embryo Injection Technology with Broad Applicationson April 26, 2024 at 10:50 am
technology could be used not merely as a tool in genetic experiments but also as an aid in avoiding the extinction of many species through cryopreservation, a methodology whose effectiveness has been ...
- Automated machine learning robot unlocks new potential for genetics researchon April 26, 2024 at 9:10 am
University of Minnesota Twin Cities researchers have constructed a robot that uses machine learning to fully automate a complicated microinjection process used in genetic research.
- Sanctuary AI’s latest 7th-generation Phoenix learns tasks in just 24hrson April 26, 2024 at 8:58 am
This new model has been unveiled in less than a year after the release of its 6th-generation bot and less than 16 months after the launch of its 5th-generation Phoenix in January 2023.
via Google News and Bing News