Driving system and actuator

Details Driving system and actuator Driving system and actuator

2000-12-18

2003-06-10

Dougherty, Thomas M. (Department: 2834)

Electrical generator or motor structure

Non-dynamoelectric

C091S006000, C623S026000

Reexamination Certificate

active

06577039

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a driving system and actuator using an intercalation substance. More particularly, the invention relates to a driving system configured to convert a chemical energy supplied by using an intercalation substance directly into a mechanical energy and externally work with a driving force derived from the mechanical energy, which is suitable for application to technical fields of artificial intelligence robots, microelectronics, medical services, and so forth.
2. Description of the Related Art
Most of currently available actuators are electrically driven actuators, such as like electromagnetic motors and electrostrictive devices (piezoelectric devices), and those driven by fluid pressures, such as hydraulic actuators and pneumatic actuators. As far as they are used in various kinds of automated factory machinery and various kinds of transport machinery, existing actuators exhibit practically sufficient performances.
However, for use in autonomous robots under the need for emergent development, for example, actuators are required to operate with three-dimensional freedom of motion in cooperation with each other. In such cases, a force exerted by an actuator and its weight becomes a load to another actuator, and therefore, as the freedom increases, difficulty in controllability and total weight increase enormously. In these applications, muscle in living bodies can be said to be well-balanced actuators. In numerical values, displacement of living muscle is 50% in the direction of contraction, response time is 30 ms, developed tension is (2~10)×10
4
kgf/m
2
(2~10 kgf/cm
2
), and maximum generated output is per unit weight is (0.1~0.3)×10
3
W/kg (0.1~0.3 W/g). No actuators satisfying these all have been developed yet (Applied Physics Vol. 60, No. 3 (1991), p. 258).
Polymeric gel is being remarked as artificial muscle similar to living muscle. Although some kinds of polymeric gel drives upon application of an electric field, generally employed are mechanochemical systems (or chemomechanical systems) that repeats swelling and contraction depending upon environmental changes such as temperature, pH, solution concentration, and so on, while converting chemical reaction energies directly to mechanical energies. Mechanochemical systems, themselves, employ living muscle as well, there are no examples in artificial substances other than organic polymeric materials such as polymeric gels, rubbers and collagen, for example (T. Takamori, “Actuator Revolution”, Kogyo-chosakai, 1987). Mechanochemical systems have a lot of advantages, such as being light, soft, and noiseless, and generating no exhaust gas by combustion. However, since most of currently developed polymeric materials are in amorphous states, and their structures have no anisotropy, they are interior in dynamic strength and durability.
On the other hand, most of inorganic layered materials represented by clay mineral are called intercalation materials, and can incorporate ions and molecules between layers by application of an electric field or chemical interaction. At that time, they change in lattice constant and volume. Therefore, these materials may become the third mechanochemical systems next to living muscle and polymeric materials.
As far as the Inventor is aware, as actuators using intercalation materials, there are currently those disclosed in:
Japanese Patent Laid-Open No. hei 02-131376
Japanese Patent Laid-Open No. hei 04-127885
Japanese Patent Laid-Open No. hei 05-110153
Japanese Patent Laid-Open No. hei 06-125120
Summarizing these actuators, the actuator disclosed in Japanese Patent Laid-Open No. hei 02-131376 has a structure sandwiching an electrolytic polyethylene oxide by graphite inter-layer compound such that flexion occurs by transpiration of Li between layers. The actuator disclosed in Japanese Patent Laid-Open No. hei 4-127885 is one of a series using Ag
0.7
V
2
O
5
as its positive
egative poles and using 4AgI-Ag
2
WO
4
as its solid electrolyte. These actuators are such that ions are intercalated by application of an electric field and a change in volume is used as a driving force. Actuators disclosed in Japanese Patent Laid-Open No. hei 05-110153 and Japanese Patent Laid-Open No. hei 06-125120 are such that an electric field is applied from the exterior to a compound prepared by inserting a polar organic substance such as amine to an organic layered substance such as clay mineral, and displacement is obtained by changing the orientation angle of the organic substance existing between inorganic layers.
As reviewed above, all of conventional actuators using intercalation substances employ a driving system by application of an electric field and no reports have heretofore taught direct conversion of chemical energies to mechanical energies.
On the other hand, according to the knowledge of the Inventor, it can be expected that advanced actuators used in artificial intelligence robots or autonomous robots requiring drive portions having great freedom can obtain excellent properties that living muscle has.
However, as already discussed above, because it is only polymeric materials that conventional systems can be artificially made of, most of them are amorphous and their structures have no anisotropy, they have drawbacks in mechanical strength and durability.
OBJECT AND SUMMARY OF THE INVENTION
It is therefore an object of the invention to provide a driving system using an actuator that uses an intercalation substance and becomes a new mechanochemical system removing those drawbacks.
Toward solution of the above-mentioned problems involved in the conventional techniques, the Inventor made researches and reviews that are summarized below.
As discussed above, all actuators using conventional intercalation substances were of types driven by application of electric fields. Through various reviews, the Inventor has come to the conclusion that the most suitable advanced actuator would be an actuator of a mechanochemical system using an intercalation substance and driven by converting chemical energies supplied by a solution directly into mechanical energies. This actuator is driven by a chemical technique, more particularly, by ingress and egress of a guest substance in and from a space between layers of an inorganic layered substance as a host substance due to chemical interaction by a supply of a solution from the exterior. This actuator can be configured as a muscle-shaped actuator (artificial muscle) creating giant displacement by using a single-crystal or c-axis-oriented film as the intercalation substance and stacking it in the c-axis direction that is the direction of expansion and contraction. Especially by using inorganic molecules having a large molecular length, giant displacement can be obtained more effectively.
The present invention has been made based the above-outlined reviews.
Toward a solution of the above-discussed problems, according to the invention, there is provided a driving system comprising:
an actuator using an intercalation substance and driven by exchange of solutions or by changing concentration of a solution; and
solution supply means for supplying the actuator with driving solution.
In the present invention, although the actuator is typically immersed in the solution supplied from the solution supply means, its entirety is not always in contact with the solution, but only a part thereof may be in contact with the solution. The solution contains a guest substance as explained later.
The actuator may comprise either a single element (module or unit) or a combination of a plurality of elements to obtain a desired size.
Basically, the actuator may have any shape, and it is designed in accordance with the purpose of its use. More specifically, the actuator may be in form of a cylinder or a prism having its axis in expansion and contraction direction of the intercalation substance, or a fiber. Preferably, for the purpose of its shape upon changes in distance between layers caused by intercalation reactio

Affiliated with

Also associated with

Rating

Driving system and actuator does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Driving system and actuator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Driving system and actuator will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3106193