CN111515941A

CN111515941A - Soft robot based on pH sensitive type hydrogel driver

Info

Publication number: CN111515941A
Application number: CN202010525245.1A
Authority: CN
Inventors: 蒋薇; 于淼; 王中格; 赵武; 张凯; 陈领; 郭鑫; 于泽源; 曹娟; 於辉
Original assignee: Sichuan University
Current assignee: Sichuan University
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2020-08-11

Abstract

The invention discloses a soft robot based on a pH sensitive hydrogel driver, which comprises a head part and a driving part connected with the head part, wherein the head part is a hemispherical flexible shell and comprises the head part and the driving part connected with the head part, the driving part comprises a plurality of flexible supporting plates which are connected to the lower end of the head part in a circumferentially and uniformly distributed mode and a plurality of hydrogel filaments which are arranged on the flexible supporting plates in parallel along the extending direction of the flexible supporting plates, tail fins are arranged at the tail ends of the flexible supporting plates, and the hydrogel filaments are pH sensitive hydrogel filaments. The robot adopts pH sensitive hydrogel as a driver, can continuously and stably work in an acidic or alkaline liquid environment, has good biocompatibility, environmental adaptability and response capability, and has the advantages of low toxicity, portability, flexibility, low noise and wide application range.

Description

Soft robot based on pH sensitive type hydrogel driver

Technical Field

The invention belongs to the technical field of robots, and particularly relates to a soft robot based on a pH sensitive hydrogel driver.

Background

The robot is a product integrating multiple subject technologies such as automatic control theory, computer, mechanical electronics, materials science and the like, and mainly has the main functions of replacing human beings to carry out repetitive work and replacing human beings to carry out work in dangerous or difficultly involved work environments. At present, the robot is widely applied mainly in the industrial field, and also has certain application in the fields of medicine, military, building industry, even service industry and the like. With the continuous progress of related subject technologies, more and more diversified robots, such as soft robots, micro robots, bionic robots, etc., are developed to adapt to the increasing productivity of human beings and the exploration of unknown fields.

Soft robots have many advantages over traditional robots. The traditional robot is usually driven by a motor, is driven by gears, teeth, connecting rods and the like, is provided with a detection system mainly based on a sensor and a control system mainly based on a microcomputer, and has the defects of poor environmental adaptability and response capability, high noise, low transmission efficiency, large inertia, difficulty in working in an acidic or alkaline complex environment and the like although the traditional robot has sufficient power, high power and good mechanical performance. Some living beings in nature have extremely high degree of freedom and extremely strong environmental adaptability and provide a new idea for the research and development of robots, and soft robots which are designed by taking the living beings as prototypes and driven by intelligent materials well overcome the defects. Compared with the traditional robot, the soft robot has the advantages of good environmental adaptability, portability, flexibility, low noise, flexibility and the like, and can adapt to more complex working environments.

At present, a plurality of soft robots capable of realizing crawling, swimming, grabbing, jumping and other actions are applied to the fields of military affairs, rescue, aerospace, medicine and the like. For example, in the medical field, a soft robot applied to a Minimally Invasive Surgery (MIS) can greatly reduce the operation difficulty of a medical doctor, which takes advantage of the higher degree of freedom of the soft robot compared to a conventional medical instrument. A soft robot researched by the academy of technology of Massachusetts can be installed on both sides of the heart to perform rhythmic compression and torsion, and replaces the traditional Ventricular Assist Device (VAD), because the better biocompatibility of the soft robot can effectively reduce the possibility of thrombus of a patient caused by VAD. Like a KISS soft robot developed by stanford university, the body can be extended to dozens of times of the original length by using an air pressurization mode, and the body can avoid obstacles or drill into narrow gaps when being extended due to the fact that the body is made of soft materials, so that the body can be applied to the fields of surveying, rescuing and the like. The increasingly diverse structures and advanced materials of soft robots make them potentially promising in the future.

Disclosure of Invention

Aiming at the technical problem that drivers of the traditional robots in the prior art are mostly made of metals which are not resistant to acid and alkali corrosion, so that the drivers are difficult to work in the complex acidic or alkaline environments, the invention aims to provide a soft robot based on a pH sensitive hydrogel driver, wherein the robot adopts the pH sensitive hydrogel as the driver and can continuously and stably work in the acidic or alkaline liquid environments.

In order to solve the technical problems, the soft robot based on the pH sensitive hydrogel driver comprises a head and a driving part connected with the head, wherein the head is a hemispherical flexible shell and comprises the head and the driving part connected with the head, the driving part comprises a plurality of flexible supporting plates which are connected to the lower end of the head in a circumferentially and uniformly distributed mode and a plurality of hydrogel filaments which are arranged on the flexible supporting plates in parallel along the extending direction of the flexible supporting plates, tail fins are arranged at the tail ends of the flexible supporting plates, and the hydrogel filaments are pH sensitive hydrogel filaments.

In the technical scheme of the soft robot based on the pH-sensitive hydrogel driver, the pH-sensitive hydrogel silk is used as the driver of the robot, and the pH-sensitive hydrogel is one of intelligent hydrogels and has the common properties of the hydrogels. When the pH value of the environment changes, the pH sensitive hydrogel can swell to a certain degree, and the volume form changes along with the change of the pH value, so that the hydrogel can be used as an intelligent driving material to be applied to the field of flexible robot driving. The invention outputs the force generated by the deformation of the hydrogel to the connecting piece (flexible supporting plate), and realizes the power and steering functions of the soft robot by controlling the shrinkage or the stretching of the hydrogel silk. The hydrogel silk in the invention can adopt pH sensitive hydrogel silk commonly used in the field, such as SA/PNIPAM hydrogel, sodium alginate Oxide (OSA) crosslinked SA/Ge composite hydrogel or P (St-DVB-MAA) hydrogel, etc.

In the technical scheme of the soft robot based on the pH sensitive hydrogel driver, the head is mainly used for balancing weight to enable the gravity and buoyancy of the robot to be mutually offset, so that the soft robot is stressed and balanced in the vertical direction, and the phenomena of deflection and the like can not occur during movement to influence horizontal movement. The head, the supporting plate and the tail fin are all made of flexible materials which are commonly used in the field and resistant to acid and alkali corrosion; the acid and alkali corrosion resistant flexible material includes, but is not limited to, natural rubber, polypentadiene rubber, styrene-butadiene rubber, polybutadiene rubber, ethylene propylene rubber, butyl rubber, chloroprene rubber, nitrile rubber, polysulfide rubber, silicone rubber, polyurethane rubber, and the like. The size of the head and the flexible supporting plate has no special proportion requirement, and the gravity and the received buoyancy of the robot are equal to each other mainly through the artificial design of the robot and the selection of body materials.

In the technical scheme of the soft robot based on the pH sensitive hydrogel driver, almost all fast swimming marine animals further develop into a new crescent tail with a large aspect ratio or a crescent tail on the basis of dark family mode propulsion, and wake flow generated when the tail fin in the crescent tail propulsion swings is a series of staggered and discrete vortexes. The fish with high-speed swimming performance is characterized in that tail fins with large aspect ratio are generally crescent or forked, tail handles are small and long, and the propulsion mode is most suitable for small-size fish-shaped robots in bionics. Therefore, the tail fin of the present invention is preferably a crescent tail fin. The lune tail fin imitating the tuna is further preferred, and the propulsion efficiency of the lune tail fin imitating the tuna is higher.

In the technical scheme of the soft robot based on the pH-sensitive hydrogel driver, the number of the flexible support plates is preferably six, and two hydrogel filaments are preferably arranged on each flexible support plate.

The soft robot based on the pH sensitive hydrogel driver provided by the invention has the following beneficial effects:

(1) the driver of the soft robot is made of pH sensitive hydrogel, the head, the supporting plate and the tail fin are made of acid-base corrosion resistant flexible materials and do not contain metal, so that the driver can continuously and stably work in an acidic or alkaline complex environment, and has good biocompatibility, environmental adaptability and response capability, small toxicity, light weight, flexibility, low noise and wide application range.

(2) This software robot adopts the head of hemisphere flexible housing and the flexible support plate that is equipped with the hydrogel silk to be as the drive division, and the mode setting of flexible support plate with the circumference equipartition is in the head lower extreme outside, and whole appearance is similar to the jellyfish in the ocean, and the resistance when the streamline shape can reduce this robot and move forward.

(3) The flexible supporting plates in the soft robot are arranged at the lower end of the head in a circumferentially and uniformly distributed manner, so that the forces generated by the flexible supporting plates in the bending driving direction perpendicular to the moving direction can be mutually counteracted, the forces generated by the hydrogel filaments on the supporting plates are combined into a force which moves forwards along the head, the soft robot cannot be deviated in other directions when moving, and the motion stability is good;

(4) the tail end of the soft robot is pushed by the swinging of the tail fins of fishes, so that the movement speed of the robot can be effectively improved, and the propelling efficiency is higher when crescent tail fins are adopted.

Drawings

FIG. 1 is a schematic structural diagram of a soft robot based on a pH-sensitive hydrogel actuator according to the present invention;

fig. 2 is a schematic view of a tail fin structure.

Description of reference numerals: 1. a head portion; 2. a drive section; 3. a flexible support plate; 4. hydrogel filaments; 5. a tail fin.

Detailed Description

So that the technical solutions of the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings, it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, belong to the present invention.

In this embodiment, the structure of the soft robot based on the pH-sensitive hydrogel actuator is shown in fig. 1, and includes a head 1 and a driving part 2 connected to the head 1.

The head part 1 is a hemispherical flexible shell and is mainly used for balancing weight, so that the gravity and the buoyancy of the robot are mutually offset, and the robot is balanced in stress in the vertical direction, and thus, the phenomena of deflection and the like can not occur during movement, and the horizontal movement is not influenced.

The driving part 2 includes a flexible supporting plate 3 and a hydrogel filament 4. The number of the flexible supporting plates 3 is six, and the flexible supporting plates are connected to the lower end of the head part 1 in a circumferentially and uniformly distributed mode. Twelve hydrogel filaments 4 are provided, each flexible support plate 3 is connected with two hydrogel filaments 4, and the two hydrogel filaments 4 are arranged in parallel along the extending direction of the flexible support plate 3. The tail end of the flexible supporting plate 3 is provided with a tail fin 5, as shown in figure 2, the tail fin 5 is in a crescent shape imitating a tuna.

In this embodiment, the head is made of nitrile rubber, and the flexible supporting plate and the tail fin are made of chloroprene rubber. Hydrogel silk 4 is pH-sensitive SA/PNIPAM hydrogel silk.

The following is a brief description of the motion principle of the soft robot based on the pH-sensitive hydrogel driver in this embodiment to further demonstrate the advantages of the present invention.

The pH value of the environment where the hydrogel silk 4 is located is controlled, the hydrogel silk 4 swells, the flexible supporting plate 3 is driven to stretch, the deformation amount along the axial direction is far larger than that along the cross section, the deformation amount of the hydrogel can be approximately regarded as deformation along the axial line, and tensile force along the axial line direction is generated. Therefore, the force generated by the driver is combined into a force which is forward along the head, and the soft robot cannot be deviated in other directions when swimming.

If the PH value of the environment where the robot is located changes, the motion amplitude of the robot changes. The greater the change in PH, the greater the change in the amplitude of the robot motion. When the external pH environment changes, the hydrogel silk is stimulated to respond, swelling and deswelling occur, the deformation of the hydrogel silk is equivalent to that a pulling force towards the head is applied to the tail end of one side of the flexible support body, and the flexible support body can be bent after the moment of the acting force is applied.

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims

1. A soft robot based on a pH sensitive type hydrogel driver is characterized in that: including head (1) and drive division (2) be connected with head (1), head (1) is the flexible casing of hemisphere, drive division (2) include a plurality of modes with the circumference equipartition connect in flexible backup pad (3) of head (1) lower extreme and along flexible backup pad (3) extending direction parallel arrangement in flexible backup pad (3) a plurality of hydrogel silk (4), the end of flexible backup pad (3) is equipped with tail fin (5), hydrogel silk (4) are pH sensitive type hydrogel silk (4).

2. The pH-sensitive hydrogel actuator-based soft robot of claim 1, wherein: the tail fin (5) is a crescent tail fin (5).

3. The pH-sensitive hydrogel actuator-based soft robot according to claim 1 or 2, wherein: the tail fin (5) is a crescent tail fin (5) imitating a tuna.

4. The pH-sensitive hydrogel actuator-based soft robot according to claim 1 or 2, wherein: the number of the flexible supporting plates (3) is six.

5. The pH-sensitive hydrogel actuator-based soft robot of claim 3, wherein: the number of the flexible supporting plates (3) is six.

6. The pH-sensitive hydrogel actuator-based soft robot of claim 4, wherein: two hydrogel filaments (4) are arranged on each flexible supporting plate (3).

7. The pH-sensitive hydrogel actuator-based soft robot of claim 5, wherein: two hydrogel filaments (4) are arranged on each flexible supporting plate (3).

8. The pH-sensitive hydrogel actuator-based soft robot according to claim 1 or 2, wherein: the pH sensitive type hydrogel silk is one of SA/PNIPAM hydrogel silk, sodium alginate cross-linked SA/Ge composite hydrogel silk or P (St-DVB-MAA) hydrogel silk.

9. The pH-sensitive hydrogel actuator-based soft robot according to claim 1 or 2, wherein: the head, the supporting plate and the tail fin are made of acid-base corrosion resistant flexible materials; the acid and alkali corrosion resistant flexible material is one of natural rubber, polypentadiene rubber, styrene butadiene rubber, polybutadiene rubber, ethylene propylene rubber, butyl rubber, chloroprene rubber, nitrile rubber, polysulfide rubber, silicon rubber and polyurethane rubber.