Background: Pharmaceutical preparation is a kind of finished pharmaceutical product made by combining raw materials with various auxiliary materials in a certain form. At present, the field of pharmaceutical preparations can meet most drug needs, but there are some limitations. It is difficult to realize the production of personalized preparations. Because 3D printing technology has the ability of precise dose control and flexible shape customization, it can realize precise control of drug dosage, release behavior and local targeting in pharmaceutical preparations. Therefore, in medicine, 3D printing technology is increasingly used in the field of pharmaceutical preparations. 3D printing technology provides an important means for new drug printing and personalized drug customization of pharmaceutical preparations in the medical field. The 3D printing technology of drugs will inject fresh vitality into individualized drug delivery. Therefore, the development trend of 3D printing technology for pharmaceutical preparations has attracted more and more attention. Objective: In order to optimize the wide application of 3D printing technology in pharmaceutical preparation, 3D printing technology such as inkjet 3D printing technology, extrusion 3D printing technology and laser 3D printing technology were studied. Methods: In this paper, the selection, classification and introduction of 3D printing technology such as inkjet 3D printing technology, extrusion 3D printing technology and laser 3D printing technology in pharmaceutical preparations are reviewed. Results: Through the investigation of various patents of 3D printing technology applied to pharmaceutical preparation in medicine, this paper summarizes and analyzes the main problems of 3D printing technology applied to pharmaceutical preparations, such as printing stability, production quality, etc. In addition, the development trend of 3D printing technology is also discussed. Conclusion: Optimization of various 3D printing technologies applied to pharmaceutical preparation in medicine is beneficial to improve printing stability and production quality in medicine. More related patents will be invented in the future.

Background: Friction stir welding technology is widely applied in the welding of dissimilar metal materials because of its characteristics of high welding efficiency, low welding process cost, high welding joint strength and reliability, and green environmental protection. The research on the processing methods and working principle of friction stir welding of dissimilar metals is beneficial to improve the mechanical properties of the joint and reduce weld defects. Therefore, the development of reliable friction stir welding technologies for dissimilar metals joining has been paid an increasing attention in recent years. Objective: To satisfy the processing of various dissimilar metals, improve the joint performance and weld defects, friction stir welding has developed bobbin tool friction stir welding and stationary shoulder friction stir welding. Methods: This paper retraces various current representative patents relative to friction stir welding, bobbin tool friction stir welding and stationary shoulder friction stir welding. Results: Through the investigation of a large number of patents on friction stir welding, the main current existing problems such as poor mechanical properties of the joints and defects in the welds are summarized and analyzed. In addition, the development trend of friction stir welding in dissimilar metal welding is also discussed. Conclusion: The research on friction stir welding methods and devices is beneficial to improve the mechanical properties of welded joints and reduce weld defects. More correlative patents will be invented in the future.

Background: Fruit and vegetable picking, as the most important part of fruit and vegetable production, is a labor-intensive industry. Fruit and vegetable picking robots can effectively improve the efficiency of picking and reduce labor requirements. As the most important part of the picking robot, the picking end-effector effectively plays a key role in improving the picking efficiency and ensuring the whole-ness of the fruit. Therefore, the development trend of picking end effectors has received more and more attention. Objective: The study aimed to solve the problems of high labor consumption and low picking efficien-cy of manual picking; thus, the grasping method of the picking end effector has been continuously im-proved. Methods: This article has presented various representative patents related to the picking end effector, such as the suction end effector, multi-finger end effector, and bionic end effector. Results: Through the investigation of a large number of picking end effector patents, the current prob-lems, such as low accuracy and large clamping damage, are summarized and analyzed. In addition, the future trends of fruit and vegetable picking end effectors are discussed. Conclusion: The optimization of the picking end effector is conducive to reducing manual labor and improving the picking rate of fruits and vegetables. More relevant patents will be invented in the future.

Background: With the increasing number of patients with cardiovascular and respiratory diseases, medical stents are needed to reshape the blood vessels and trachea to restore their function. Due to its high degree of standardization, the existing medical stent manufacturing technology is mature and suitable for most groups. However, conventional medical stents are not suitable for every patient due to the patients’ individual differences and other reasons. Hence, patients need custom medical stents. Therefore, 3D printing technology with high customization function as an emerging stent manufacturing method has attracted much attention in recent years. Objective: By solving the problem of poor matching rates between traditional medical stents and human body channels, 3D printing technology will continue to develop in the medical stent manufacturing field. Methods: This study traces the representative patents related to the vascular stent and tracheal stent manufacturing based on 3D printing technology. Results: Through the analysis of numerous patents about 3D printed vascular stents and tracheal stents, the reasons for the mismatched medical stent specifications and low efficiency are summarized. The challenges in the development of 3D printing medical stents are discussed. Conclusion: Research on the 3D printing of medical stents is conducive to improving patients’ suitability and medical stent implantation and reducing the time cost. More patents will be invented in the future.

Background: The overflow valve, as an essential pressure control element, is widely applied in various hydraulic transmission systems because of its characteristics of constant pressure overflow, stable pressure, system unloading and safety protection. The research on the structure and working principle of the overflow valve are beneficial to improve the working efficiency and operating stability of pressure control of the hydraulic transmission. Therefore, the development trend of the overflow valve for pressure control has been paid more and more attention. Objective: To meet the growing demands for the working efficiency and operating stability of hydraulic transmission, the structure of the overflow valve for pressure control such as direct-acting overflow valve and pilot-operated overflow valve is being improved continuously. Methods: This paper retraces various current representative patents relative to the structural device of direct-acting overflow valve and pilot-operated overflow valve for pressure control. Results: Through investigating a large number of patents on the overflow valve for pressure control, the main current existing problems such as low working efficiency and poor operating stability are summarized and analyzed. Moreover, the development tendency of the overflow valve for pressure control in the future is also discussed. Conclusion: The optimization of the structure of the overflow valve for pressure control is conducive to improve working efficiency and operating stability. More correlative patents will be invented in the future.