Song Xiaofeng, Tan Shili
(School of Mechanical and Electronic Engineering and Automation, Shanghai University, Shanghai 201800)
Abstract: Micro-robot is an important branch of microelectromechanical systems, and it has been attracting a lot of attention in recent decades, due to its ability to enter the narrow space where humans and macro-robots cannot work. In recent decades, it has received extensive attention. This paper firstly gives several kinds of micro-robots that have appeared in recent years at home and abroad, analyzes their characteristics and performance, discusses several key problems encountered in the research of micro-robots, and points out the main research and development direction of these fields in the coming period of time.
Keywords: microrobot; microactuator
In recent years, microsatellites, microflights
and microrobots using MEMS technology have demonstrated attractive applications and strategic significance for dual-use applications. Therefore, as one of the development directions of microelectromechanical systems technology
, the research on micro-robotics based on precision machining
has become a hot spot in the international arena, which is not only driven by a strong market, but also by the participation of many research institutes. Many countries represented by Japan
have carried out a lot of research in this area, focusing on
the development of micro-robotics to enter the narrow space of industry, medical microsystems to enter the narrow space of the human body
and micro-factories. Domestic in the national natural science fund
fund, 863 high-tech research and development programs, such as funding, Tsinghua University
University, Shanghai Jiao Tong University, Harbin Institute of Technology, Guangdong University of Technology
University, Shanghai University and other research institutions for micro-robotics and micro-operation systems
study a lot of research, and were developed the principle of the prototype. At present, the research on micro-robots in China is mainly focused on three fields[6]: (1)
Micro-robots
for the detection of small pipelines in gas, chemical, and power generation equipments. (2)
Micro-machines for non-invasive diagnosis and treatment of the human body, into the intestinal tract
Man. (3) Micro-machines for non-disassembly maintenance of complex mechanical systems
Human.
1 Development and research status of micro-robot
Based on the actual situation of micro-robot research in China, we
focus on micro-plumbing robots, non-invasive micro-medical robots, and micro-robots for
special operations.
111 Micro pipeline robots
Micro pipeline robots are based on the background of narrow space applications
, whose environment is characterized by walking into
inspections, repairs, and other operations in narrow tubular passages or crevices. Because of the obvious difference with the conventional conditions of the pipe working environment
, its walking mode and structural principle are also different with the conventional pipeline robot
, so it is not feasible to scale down the pipeline robot according to the conventional technological means
. In view of this, the
walking method of micro pipeline robot should be a different way. In recent years, with the development of microelectromechanical technology and the development of crystal piezoelectric effect and super magnetostrictive material magneto-mechanical coupling
technology applications, so that the emergence of a new type of microdriver and application of the
reality. The research results of microactuators have become an important
foundation for the development of microtubular robots[1].
A micro pipeline robot has been developed at Nagoya University in Japan, which can be
used for inspection of tiny pipes and for tiny work in small spaces in the biomedical field. The robot can be driven by an electromagnetic coil outside the pipe
and does not need to be powered by a cable. The spiral-type tube-moving micro-robot developed by Tokyo Institute of Technology and NEC
in Japan has a maximum speed of 260 mm/s and a maximum traction force of 12 N in a straight tube with a diameter of
Φ2514 mm.
The maximum
movement speed of this kind of micro-robot is 5mm/s, the load can be up to 20N, it has high motion
precision, large load, but the motion speed is slow and the structure is complicated.
Shanghai University and Shanghai Jiao Tong University in China have developed inertial
impact pipeline micro-robots, the micro-robot of Shanghai Jiao Tong University is driven by a
layered piezoelectric actuator; the micro-robot actuator of Shanghai University has two types of laminar and dual piezoelectric film[3]. Figure 1 shows the kinematic mechanism of a dual piezoelectric film microtubing robot, which adopts a dual
piezoelectric film actuator to increase the driving
force and improve the load carrying capacity compared with a single piezoelectric film. The mechanism can move at a maximum speed of
15mm/s, with forward, backward, upward and downward functions.
112 Development of micro medical robots
In recent years, medical robotics research and application development
expanding rapidly, micro medical robots is one of the most promising application
area, according to the Japan Science and Technology Policy Research Institute predicted that by 2017
medical field using miniature machines and robots will exceed all
surgical procedures. According to the Japan Science and Technology Policy Research Institute, by 2017
more than half of all
medical surgeries will be performed using micromachines and robots. As a result, Japan has a plan to adopt "robot surgeons" and is developing ultra-miniature robots that can travel through human blood vessels and be used to
detect and kill cancer cells. The John Hopkin Laboratory in Maryland, USA
has developed a "smart pill," which is actually
a miniature detection device equipped with a miniature silicon thermometer and miniature circuits,
which, when swallowed, sends information about the body's temperature to a recorder. Swedish
scientists have invented a robot the size of an English punctuation mark that could move a single cell or capture bacteria in the future to perform
various surgeries inside the body.
Many research institutes in China have mainly carried out research on non-invasive miniature
medical robots, and have achieved some results. The non-invasive medical robot
is mainly used in the medical treatment of diseases in the human body's internal cavity, which can greatly reduce
reduce or eliminate the serious discomfort and pain
brought by the various types of endoscopes, internal syringes, internal
delivery devices and other medical devices used in the clinic to the patients. The University of Science and Technology of China (USTC), with the support of the National Natural Science Foundation of China (NSFC), has developed a piezoelectric ceramic-driven multi-segmented serpentine traveling laparotomy micro-robot, which installs a CCD camera system, surgical instruments and intelligent control system at the end of the micro-robot, and then extends into the abdominal cavity to perform surgery through the small openings in the patient's abdomen. Through a small opening in the patient's abdomen, the micro-robot is inserted into the abdominal cavity to perform surgery. Its features
are fast response speed, high precision of movement, large force and range of motion
, and each section can realize rapid and flexible movements within ±60° in the direction of two degrees of freedom, as shown in Figure 2, which shows the scene of surgery using a laparotomy robot[5]. Zhejiang University has also developed the principle prototype of a non-invasive medical
mini-robot, which enters the human body's internal cavities (e.g., intestines, esophagus) in a levitation mode to avoid damaging the organic tissues of the human body's internal cavities, and has a fast operating speed and convenient speed control.
113 The development of special operations micro-robot
In addition to the above mentioned micro pipeline robots and non-invasive micro
medical robots, a number of researchers at home and abroad have carried out extensive
research on special operations micro-robot. This kind of micro-robot with
equipped with the appropriate sensors and operating devices, in the military and civilian aspects of the
very good prospects for development.
The U.S. National Security Laboratory has produced the world's smallest robot ever, which weighs less than 28g, has a volume of
411cm3, and a leg mechanism of belt conveyor, which can be used to replace
human to complete many dangerous jobs. The U.S. Navy invented a miniature
city search and rescue robots, the robot has been in 2001 "9111" incident
after the World Trade Center debris search and rescue site to show their skills. Japan's Mitsubishi Electric
subsidiary, Matsushita Tokyo Research Institute and Sumitomo Electronics Corp. have jointly developed a micro-robot the size of an ant, which can enter
very confined environments to perform repair work, and which has two
circular connectors on either side of its body that can be connected to other robots to accomplish special
tasks.
The robot has two round connectors on either side of its body that allow it to connect to other robots for specialized tasks.
Because creatures in nature have certain functions
that human beings can not match, so in recent years the use of natural biological behavior and certain functions
can be used to design robots and achieve flexible control, by robotics
scholars have paid extensive attention to. There are many universities and research institutes in China that are carrying out
research on miniature bionic robots. Based on the principle of bionics, Shanghai Jiao Tong University has developed a miniature six-legged bionic
robot with a small size and good mobility by using six sets of parallel planar four-link mechanisms, a miniature DC
motor, and a corresponding deceleration and torsion mechanism. The robot has a length of
30 mm, a width of 40 mm, a height of 20 mm, a weight of 613 g, and a walking speed of
3 mm/s[2] . Some research work on micro-bionic robots
has also been carried out at Shanghai University.
2 Problems in the development of micro-robot
(1) Miniaturization of driver
Micro-driver is the most important component of MEMS, from the perspective of micro-robot
development, micro-driver technology plays a key role, and it is a symbol of the level of micro-robot
robot level, the development of energy-consuming, simple structure, easy to miniaturize, displacements and displacement, and the development of micro-robot is the key to the development of MEMS, and the development of the micro-driver technology is the key to the development of micro-robot.
Chemical, displacement and force output, good linear control performance, dynamic response
Response to a new type of drive (high-performance piezoelectric elements, high-torque micromotor
Da) is the future direction of research.
(2) Energy supply
Many actuators are driven by electrical energy, but for micro
mobile robots, the supply of electrical wires will seriously affect the movement of micro
robots, especially in the curvature of the environment is relatively large changes.
The development trend of micro-robot should be cable-free, energy, control signals and
and detection signals should be able to send and transmit cable-free. In order to be truly
practical, micro-robots must solve the problem of cable-free microwave energy and cable-free data transmission technology
technology, as well as research and development of small size and high-capacity battery.
(3) Reliability and safety
Many of the micro-robots currently being developed are based on medical
, military, and nuclear power plants as the application background, and the reliability and safety of the robot's work in these very important
applications is an issue that the designers must take into account, and the robot is required to be able to adapt to the environment in which it is operating.
Adaptation to the environment and troubleshooting capabilities[4].
(4) New micro-mechanism design theory and finishing technology
Micro-robots and conventional robots are not simply scaled down in terms of structure
, but their development is closely related to the development of micro-drivers and finishing
technology to a certain extent. At the same time, designers are required to innovate in
structural design theory, and to study the appropriate micro-robot moving
movement mechanism and movement mode.
(5) Highly Autonomous Control System
The micro-robot to complete a specific job, its own localization and environment
recognition ability is the key, the development of micro-vision system, improve the micro-image processing
processing speed, the use of neural networks and artificial intelligence and other advanced technologies to solve
highly autonomous control system is the ultimate realization of the problem of
highly autonomous
practice.
The key to the final realization of the practical
key.
3 Conclusion
Micro-robotics is still in the period of theoretical exploration in the laboratory, and there is still a considerable distance from the practicalization
. There are many key technologies that have not been solved
, and the solution of these problems will lead to the development of many related disciplines
. Only when these problems are solved, the actualization of micro-robot
will become possible. We need to be innovative, seize this cutting-edge
topic, the micro-robotics technology to the national economic construction and development of
influential areas.