Instead of manual handling of objects, we usually think of robotic arms, whose grippers can easily pick up the objects we want to move, and quickly and accurately place them where they should be.
At the moment when the manufacturing industry is turning to intelligence, the application of this technology has become commonplace, but the grippers are not necessarily mechanical devices.
Plastics with memory can also be good porters.
A few days ago, a team led by Professor Song Jizhou of the School of Aeronautics and Astronautics of Zhejiang University put forward a new concept of gripper.
They called it the "universal gripper", which can "lock" the target object in the body and easily grasp and place 1 micron to 1 micron.
Objects of various shapes and sizes of meters.
However, although it is known as omnipotent, the structure of the gripper is not complicated, and its carrier is only a piece of shape memory polymer material called "smart plastic".
Shape memory polymer is a new type of functional polymer material, which belongs to a new branch of polymer material research, development and application.
It can have the characteristics of plastic and rubber.
At present, shape memory polymers have been widely used, such as smart fabrics, heat shrinkable films for electronic packaging tubes, solar pirated unfolding structures for aircraft, and smart medical devices.
The magic of this material is that the properties of the polymer can be controlled by external stimuli such as light and heat, and it can be changed between soft and hard.
When it is subjected to a certain external force, it can maintain the current degree of deformation, and then restore it by changing the external stimulus conditions, so as to realize the grasping and placing of the object.
This research is based on this phenomenon.
Researchers embed the object or the surface structure of the object in the soft state of the shape memory polymer, and then change the stimulus conditions to convert the polymer into a rigid state and maintain the embedded state.
Temporary shape, so as to grasp the object, and then after the completion of the transfer work, the polymer is restored to the initial state by applying an external stimulus again, and the grasped object is released, thus completing a transport.
In this process, the polymer as a "gripper" can be used to grasp different objects by changing its shape arbitrarily, which is called a "universal lock".
Professor Song Jizhou said that this "universal lock" can produce great grip on typical three-dimensional structural objects, including spheres, squares, tubular objects, bolts, nuts, date nuclei, keychains, etc.
; not only that, but it also It can adhere to the surface of the object, like a gecko, regardless of whether the surface of the object is smooth or rough.
This new handling method has also aroused the interest of scientists in exploring its application fields.
They reduced the size of the object to a microscopic scale to observe the handling effect of the gripper.
Under this condition, the surface force of the object, especially The strong adhesion of the gripper brings greater challenges to the release of objects.
The countermeasure of scientists is to coat the polymer surface with a special material or increase the roughness of the contact surface to weaken the adhesion of the polymer surface, and only lock the object or the surface structure of the object inside it.
In this way, without relying on adhesion, not only the accurate handling of tiny parts can be realized, but also the trouble caused by adhesion when the object is released can be solved, even if it is 75 microns in size.
Irregular iron particles or silica balls with a diameter of 10 microns can also be released from the gripper smoothly.
Professor Song Jizhou said that in the preparation of flexible electronics, the rapid assembly process of micro-components is very important, that is, the transfer of tens of thousands or more of the micro-nano components on the prepared substrate to the flexible substrate.
At present, the commonly used method is to realize the one-time grasping of these components through adhesion, but the adhesion also becomes a limiting factor when released.
In the "universal gripper" scenario, the transfer of microscopic components can get rid of the adhesion effect.
This research also provides a new idea for the preparation of flexible electronics, which is of great help to the industrialization process of flexible electronics.