Researchers were puzzled to see the DNA rods organise themselves

THE ROTORS DRAW ENERGY FROM WATER THAT IS INDUCED BY APPLYING VOLTAGE OR BY HAVING DIFFERENT CONCENTRATIONS OF SALT ON EITHER SIDE OF THE MEMBRANE.

• The team has used a technique called DNA origami for the motor
• The study was recently published in Nature Physics
• Development has opened new avenues in the engineering of active robots

Rotary motors that are driven by some flow are in use for a long time in windmills and waterwheels. A similar mechanism is also seen in biological cells where the FoF1-ATP synthase produces the fuel required by cells to function. Drawing inspiration from this, researchers at the Delft University of Technology have developed the smallest ever flow-driven motor from DNA that utilises electrical or salt gradients to generate mechanical energy. For the construction of the motor, the team has used a technique called DNA origami which uses specific interactions between complementary DNA pairs to build 2D and 3D nano-objects.

The rotors draw energy from water that is induced by applying voltage or by having different concentrations of salt on either side of the membrane. From the observations made, researchers have explored more and used the knowledge to build nanoscale turbines.

“Our flow-driven motor is made from DNA material. This structure is docked onto a nanopore, a tiny opening, in a thin membrane. The DNA bundle of only 7-nanometer thickness self-organises under an electric field into a rotor-like configuration, that subsequently is set into a sustained rotary motion of more than 10 revolutions per second,” explained Dr Xin Shi, a postdoc in the department of Bionanoscience at TU Delft. Dr Shi is also the first author of the study published in Nature Physics.

Researchers in South Korea are developing a new health monitoring device in the form of an e-tattoo that can automatically alert the wearer to potential health problems.

The team at the Korea Advanced Institute of Science and Technology have created an electronic tattoo ink made of liquid metal and carbon nanotubes that effectively functions as a bioelectrode.

The device could be used to send a readout of the wearer’s vital signs if connected to biosensors, including for instance an electrocardiogram.

Alongside heart rates it could be used to read glucose or lactate levels for people with diabetes or sepsis.

But the researchers plan to do away with the biosensors and design the e-tattoo as a fully self-contained device.

“In the future, what we hope to do is connect a wireless chip integrated with this ink, so that we can communicate, or we can send signal back and forth between our body to an external device,” said the project leader Professor Steve Park.

The e-tattoo ink is non-invasive and doesn’t require a needle to be implanted beneath the skin like a traditional tattoo.