We’ve all seen robotic arms swinging and performing various tasks in industrial settings. So, what about miniature robots? There are tiny systems that transport minuscule amounts of liquid through fine capillaries. Developed s an aid for laboratory analysis, they are known as microfluidics or lab-on-a-chip. There are usually external pumps to move the fluid through the chips. These systems, however, are challenging to automate. Chips must be custom-designed and manufactured for each application.
Scientists led by ETH Professor Daniel Ahmed are combining conventional robotics and microfluidics. A newly developed device uses ultrasound and attaches to a robotic arm to perform micro robotic and microfluidic applications tasks. The results of the work are published in Nature Communications.
The device features a thin, pointed glass needle and a piezoelectric transducer that makes the needle oscillate. The researchers can vary the oscillation frequency of their glass needle. Dipping the needle into a liquid allows them to create a three-dimensional pattern composed of multiple vortices. The pattern depends on the oscillation frequency.
The researchers were able to mix tiny droplets of highly viscous liquids and pump fluids through a mini-channel system by creating a specific pattern of vortices and placing the oscillating glass needle close to the channel wall. Finally, they used their robot-assisted acoustic device to trap fine particles in the fluid. Large particles move toward the oscillating glass needle and accumulate. This method captures not only inanimate particles but also fish embryos. Expectations are that it will also be capable of capturing biological cells in the fluid.
Other potential applications for micro-robotic arms include sorting tiny objects in biotechnology to introduce DNA into individual cells and using them in additive manufacturing and 3D printing.