Scientists achieve femtosecond laser manufacturing of magnetic responsive Janus origami robots

The multifunctional manipulation of droplets of different scales has significant prospects in various fields, especially in precision chemistry and biomedical diagnosis. From a practical perspective, effective droplet manipulation technology requires multifunctional integration and applicability across different scales.

Magnetic excitation has been widely used in the field of droplet manipulation due to its advantages such as remote controllability, biocompatibility, insensitivity to environmental factors such as matrix charges, and excellent transparency. However, expanding the ability of magnetic responsive droplet manipulation and expanding various functions from micro to nano scale remains a daunting challenge.

In response to this challenge, Professor Hu Yanlei and his research team from the Micro/Nano Engineering Laboratory of the Chinese Academy of Sciences (CAS) and the University of Science and Technology of China (USTC) cooperated with other researchers to develop a magnetically driven Janus origami robot using femtosecond laser nano processing technology.

This robot can effectively integrate various droplet manipulation functions, including three-dimensional droplet transfer, merging, splitting, precise distribution and on-demand release of sub droplets, as well as stirring and remote heating.

In addition, this manipulation strategy exhibits significant stability and allows for the manipulation of droplets with a volume ranging from approximately 3.2 nanoliters to approximately 51.14 microliters. This research achievement is titled "Magnetic Janus Origami Robot for Omnidirectional Manipulation of Transscale Droplets" and has been published in Nature Communications.

The upper and lower surfaces of the magnetic responsive double-layer Janus origami robot exhibit different wetting characteristics. The upper surface of the robot is in a superhydrophobic state with low droplet adhesion, while the lower surface is in a hydrophobic state with high droplet adhesion.

At the same time, two creases are designed on the surface of the robot to facilitate the self sealing of droplets under capillary force during contact. The overall contour, creases, and surface micro nano functional structure of the robot are manufactured and modified through femtosecond laser scanning.

Driven by a magnetic field, the robot actively approaches and encapsulates water droplets through rolling, thereby achieving controlled water droplet transmission. In addition, the magnetic responsive double-layer Janus origami robot can distribute sub droplets from larger droplets through directional rolling and folding.

By controlling the magnetic field intensity, distributed sub droplets can be squeezed out of the robot. Using its specially designed superhydrophobic appearance, the robot gently pushes droplets to achieve controlled release and separation. The robot can also rotate under the influence of a magnetic field to achieve controlled liquid mixing, and combine its photothermal characteristics to achieve remote heating.

The development of a magnetic responsive Janus origami robot can achieve multifunctional cross scale droplet manipulation, providing functions similar to commercial magnetic stirrers. In addition to quickly mixing water, these robots can also effectively mix high viscosity liquids such as glycerol through heating and stirring functions, achieving temperatures exceeding 80 ° C.

Based on its diverse droplet manipulation capabilities, the magnetic responsive Janus origami robot seamlessly integrates various droplet processing functions to achieve continuous droplet manipulation goals. For example, robots approach water droplets autonomously through rolling motion, distribute specific volumes of sub droplets, transport these distributed sub droplets to merge with other droplets, and finally promote rapid mixing of different component droplets through stirring. This multifunctional droplet manipulation integration seamlessly extends to the nanoscale.

In the concept validation demonstration, the robot successfully completed the extraction and purification of nucleic acids after surface modification.

In summary, the magnetic responsive Janus origami robot can achieve cross scale droplet manipulation, which is of great significance for precise reagent delivery, droplet patterning, and rapid droplet reactions in different fields such as fine chemical engineering, medical diagnosis, and microfluidic technology.

Source: Laser Network