A new way to build tiny 3D devices from diverse materials
KTH researchers have found a new method for building very small, advanced 3D structures from a wide range of materials, not just plastics. This opens the door to new types of miniaturized devices for applications in areas such as medicine, environmental monitoring, advanced materials, and optical technologies.
The study was conducted by an international team of researchers. At KTH, the work was led by postdoc
Wenhai Lei
and professor
Shervin Bagheri
.
In the study, published in Nature, the researchers used a very fast laser to create heat at a precisely defined spot inside a liquid.
By controlling the heat and light, the researchers could generate a fluid flow and direct the movement of nanoparticles with diverse shapes and compositions, including metals, metal oxides, carbon nanomaterials and quantum dots. This allowed them to assemble these different materials into complex 3D structures with high precision and speed.
To demonstrate the capabilities of the technique, the researchers have created microscopic valves that can sort particles by size. They have also built tiny robots made from several different materials, which can move in different ways depending on how they are controlled by different external stimuli.
What new possibilities does this technique open up?
“It allows us to use light-driven fluid flow as a manufacturing tool. We can now rapidly build truly three-dimensional microstructures from a wide range of functional materials. This opens up new possibilities for advanced microdevices in areas such as microfluidics, photonics and microrobotics,” says Shervin Bagheri
“The most surprising aspect of the findings is how precisely fluid flow can be controlled at the microscale. By tuning thermal and hydrodynamic forces, we can switch between dispersion and assembly of nanoparticles. This shows that fluid mechanics itself can become a powerful and universal fabrication principle.”