This Tiny Flower-Like Robotic Gripper Handles the Smallest of Balls
Designed for use in microelectronic assembly and biomedical engineering, this morphing flower is stronger than it looks.
Researchers from the Beijing Institute of Technology and the Ministry of Education of China's School of Integrated Circuits and Electronics have developed a flower-like morphing robotic gripper — small enough to latch on to solder balls yet robust enough to withstand impacts of over 1,600g.
"Electrothermal microgrippers have long been sought after for their potential to simplify micro-manipulation tasks," says co-corresponding author Shuailong Zhang of the team's focus. "Our design not only meets these expectations but also exceeds them by offering a level of precision and reliability that is unmatched in the field."
The team's gripper uses a flower-like design with four "petals," designed to wrap around the object to be gripped. At those scales, though, traditional motors would be a challenge — so the gripper is based around aluminum-silicon dioxide (Al-SiO₂) bimorphs, in which temperature differences between the aluminum and the silicon dioxide can be used to close and open the gripper through the application of heat.
In testing, the gripper proved able to securely grasp microbeats measuring 400μm and weighing 0.1mg — not much, to be fair, but enough for the team to move onto a real-world application: picking up and manipulating individual solder beads for pick-and-place ball-grid array (BGA) component assembly. In this test, the gripper was used to manipulate 400μm solder beads weighing 0.25mg each while withstanding an average acceleration of 35g and impacts up to 1,600g.
"By employing a standard MEMS [Micro-Electromechanical Systems] fabrication process with commonly used materials," the researchers conclude, "the designed microgripper demonstrates promising prospects for large-scale manufacturing. The advantages of the low driving voltage, large deformation, and fast response make the microgripper a very useful tool for micromanipulation applications. Moreover, the microgripper has shown excellent capturing capability and reliable grasping strength, verified by strong vibration and impact tests."
The team's work has been published in the journal Nature under open-access terms.