rus
Some scientists believe that nanotechnology began with the invention of a scanning probe microscope, the history of which has already been discussed in this journal. This article contains an attempt to track development of the technology, on which the scanning probe microscopy is based,
and also gives examples of its patenting.
and also gives examples of its patenting.
Теги: inventions patenting scanning probe microscopy изобретение патентование сканирующая зондовая микроскопия
The technology employs a piezoelectric effect and the corresponding materials used for control of minute transfers of a probe and of an examined sample. Besides, the piezoelectric effect gave an impetus to development of a big number of other directions, which could be interesting to discuss from the point of view of patenting.
In 1880 Curie brothers discovered that, when a force was applied to certain materials (quartz, tourmaline, Seignette salt), electric discharges appeared on their surfaces. This phenomenon got the name of a direct piezoelectric effect or piezoeffect. In 1881 G.Lipman assumed, that if an electric field was created in samples, mechanical tensions would appear in them leading to a deformation. This phenomenon was dubbed as an inverse piezoeffect.
For the first time piezoeffect was used practically in 1917 for detection of submarines. Subsequently piezoelements got wide applications in microphones, phones, sound pickups and frequency stabilizers. Later they found use in almost all sectors of industry. An important stage in this sphere was development in the USSR of the first piezoceramic material – barium titanate (ВаTiO3), which gave another impetus to development of the technologies based on the piezoelectric effect.
From the point of view of patenting we should first discuss inventions in the transmitting-receiving technologies employing the piezoeffect. In particular, a piezoelectric microphone [2] was announced on July, 10th, 1947. In the invention formula a piezoelectric material was integrated with the module of precision mechanics. This gave way to an interesting solution.
However an essential drawback of the invention formula was connected with a concrete material – Seignette salt, whereas barium titanate was already synthesized three years earlier. Thus, a substitution of the material made it possible to bypass the author's certificate. The next piezoelectric telephone [3] already employed barium titanate, but the specification of the invention formula made it possible to bypass the author's certificate again due to application of new materials.
An electric signal device for detection of fish [4] integrated the piezoeffect and movement sensors, however, again there were excessive details in the formula of the invention, although such a device could be used for recording of movement of any solid objects in various liquids.
Piezoceramic is successfully used in medicine. For example, a device for determination of viscoelastic properties of muscles [5] ensured fixation of movements in them, but the same design can be used for measuring of pulse, evaluation of the efficiency of implants and many other things. Thus the invention formulas did not provide a reliable protection for the inventions because they lacked "the umbrella character".
Now it is time to discuss the question of patenting of the piezoelectric devices used as drives. In an engine (fig.1) based on a piezoceramic tube with external and internal electrodes 3 it can change its dimensions depending on the applied voltage [6]. The engine is associated with something rotating, which was typical for one of the first Russian piezomotors.
At the same time, if a invention formula was presented in an "umbellate" kind, instead of giving a concrete definition of realization of the rotor 2 and stator 1 in the first point, it would be more appropriate to describe a possibility of movement of the butt end of the tube, in the second – to add fragment allocation on its length for the axial movement, and in the third – to give additional movement of the butt end. In a particular case it is possible to use the tube as a rotation source. Then the patent would protect the engine of rotation and use of the piezotubes in the scanners for SPM. It could also protect the devices similar to a probe [7] and even a multipurpose piezoelectric module [8].
That was the beginning of an active use of the piezotubes in various areas of technologies, and another impulse was given to the process in 1980s with the invention of the first SPM. However, not so fast they occupied the leading positions in these products. The proposed devices included piezoscanners of 12 linear piezoelements on a cubic assemblage [9], of 17 rectangular elements on an orthogonal assemblage [10], on conic piezotubes [11] and piezopackages coupled with one-co-ordinate carriages suspended on elastic guides [12] with lever systems [13].
It is difficult to foresee the prospects of development of this or that direction, however any new solution should be better patented in an "umbrella" form. For example, in order to increase the umbrella covering of a patent the following elements were introduced in a micropositioner [14] with a lever system: inserts minimizing the thermodrift of the carriages; strain sensors eliminating nonlinearity, hysteresis and creep of piezoceramic; capacitor and interferential sensors of linear movements reducing the movement error of the carriages.
Also developed were rather exotic piezoscanners and micropositioners on rectangular piezobimorphs [15], however they got only limited distribution because of their insufficient rigidity. Positioners on the basis of round piezobimorphs [16] were offered, but they were not developed further because of their small movements. Besides, absence of dependent points in the formulas of inventions, in particular, descriptions of the sensors of the main and nonfunctional movements, limited the potentials of the devices.
It is necessary to point out, that employment of measuring transducers of various parameters is useful for improvement of the characteristics of many devices and increase the chances of obtaining a patent. According to foreign patent lawyers, the main drawback of the Russian applications is small volume of the so-called "meat". An idea and two or three distinctive signs can be of a breakthrough character, but usually the number of the dependent points in an invention formula is insufficient. This often does not allow us to obtain patents on interesting solutions, because an expert will find references to separate signs of the formula of the invention, which becomes simpler due to new databases and improvement of the patent search.
Getting back to the tube piezocsanners, which got basic development and are more often used in the probe microscopy than other systems, we should point out that some products were patented, which due to complex bends ensured an increased range of movements and preserved its flatness [17, 18]. Nevertheless, due to their insufficient umbrella character a patent was obtained [19], in which original polarization and connection of piezotubes were applied, and also external drives, which extended the opportunities of the device.
Also a patent was obtained [20], in which the module of the axial movement of a piezoscanner was coupled with the elastic guides, minimizing its nonfunctional movements. The piezoceramic scanners were combined with the known mechanical devices, which gave an essential technical effect with minimal costs. A tube three-co-ordinate piezoscanner [21] was integrated with copies of its functional modules simulating its movements separately by each co-ordinate. These simulators were supplied with sensors and had improved characteristics, at that, operation of the basic scanner was adjusted depending on their functioning.
It would also be appropriate to discuss examples of a bypass of an original patent. In 1990s an inertial stepper motor was developed, based on a piezoceramic package coupled with two guides [22], and a device on its basis [23]. That motor (fig.2) contained platform 1, on which carriage 2 was installed, tightened to the platform by a cover plate 3 with spring 4.
On carriage 2 piezopackage 5 was fixed connected with massive element 6 installed on supports 7 with a possibility of sliding in relation to platform 1. Sawtooth voltage was supplied to piezopackage 5. Smooth front 9 moved massive element 6 by co-ordinate X in the positive direction. At that, due to friction carriage 2 remained on its place.
In case of a voltage jump 10 (abrupt front) carriage 2 slipped on platform 1 by co-ordinate Х also in the positive direction. This principle of movement has been known for a long time, nevertheless, due to optimization of the design a patent [22] was obtained and it had a rather wide umbrella.
A decision was taken to bypass this patent [22], which became possible due to setting a task of removal of the rest of the gas between the rubbing surfaces of platform 1 (fig.3) and carriage 2 [24].
Pumpdown and freezing decreased the low-temperature sealing of carriage 2 on platform 1. Besides, the carriage was tightened to the platform by flat spring 8 fixed on bracket 9 and coupled with adjustable tightening 4 and stabilizing the movement of the carriage due to exclusion of the nonfunctional movements of cover plate 3 on co-ordinate Х. (Sawtooth voltage was supplied to piezopackage 5). In patent [25] in addition to a slightly changed system of flat springs and movement sensors introduced in it, a start module (not shown in fig.3) was added, excluding a low-temperature sealing.
Analysis of patenting of the technologies with application of piezoceramics suggests a conclusion that the main principle of development of hi-tech patents is often ignored: minimization of the first independent point and an umbrella character of the invention formula. In this case a bypass of the umbrella patents is possible, if a new task is set.
In 1880 Curie brothers discovered that, when a force was applied to certain materials (quartz, tourmaline, Seignette salt), electric discharges appeared on their surfaces. This phenomenon got the name of a direct piezoelectric effect or piezoeffect. In 1881 G.Lipman assumed, that if an electric field was created in samples, mechanical tensions would appear in them leading to a deformation. This phenomenon was dubbed as an inverse piezoeffect.
For the first time piezoeffect was used practically in 1917 for detection of submarines. Subsequently piezoelements got wide applications in microphones, phones, sound pickups and frequency stabilizers. Later they found use in almost all sectors of industry. An important stage in this sphere was development in the USSR of the first piezoceramic material – barium titanate (ВаTiO3), which gave another impetus to development of the technologies based on the piezoelectric effect.
From the point of view of patenting we should first discuss inventions in the transmitting-receiving technologies employing the piezoeffect. In particular, a piezoelectric microphone [2] was announced on July, 10th, 1947. In the invention formula a piezoelectric material was integrated with the module of precision mechanics. This gave way to an interesting solution.
However an essential drawback of the invention formula was connected with a concrete material – Seignette salt, whereas barium titanate was already synthesized three years earlier. Thus, a substitution of the material made it possible to bypass the author's certificate. The next piezoelectric telephone [3] already employed barium titanate, but the specification of the invention formula made it possible to bypass the author's certificate again due to application of new materials.
An electric signal device for detection of fish [4] integrated the piezoeffect and movement sensors, however, again there were excessive details in the formula of the invention, although such a device could be used for recording of movement of any solid objects in various liquids.
Piezoceramic is successfully used in medicine. For example, a device for determination of viscoelastic properties of muscles [5] ensured fixation of movements in them, but the same design can be used for measuring of pulse, evaluation of the efficiency of implants and many other things. Thus the invention formulas did not provide a reliable protection for the inventions because they lacked "the umbrella character".
Now it is time to discuss the question of patenting of the piezoelectric devices used as drives. In an engine (fig.1) based on a piezoceramic tube with external and internal electrodes 3 it can change its dimensions depending on the applied voltage [6]. The engine is associated with something rotating, which was typical for one of the first Russian piezomotors.
At the same time, if a invention formula was presented in an "umbellate" kind, instead of giving a concrete definition of realization of the rotor 2 and stator 1 in the first point, it would be more appropriate to describe a possibility of movement of the butt end of the tube, in the second – to add fragment allocation on its length for the axial movement, and in the third – to give additional movement of the butt end. In a particular case it is possible to use the tube as a rotation source. Then the patent would protect the engine of rotation and use of the piezotubes in the scanners for SPM. It could also protect the devices similar to a probe [7] and even a multipurpose piezoelectric module [8].
That was the beginning of an active use of the piezotubes in various areas of technologies, and another impulse was given to the process in 1980s with the invention of the first SPM. However, not so fast they occupied the leading positions in these products. The proposed devices included piezoscanners of 12 linear piezoelements on a cubic assemblage [9], of 17 rectangular elements on an orthogonal assemblage [10], on conic piezotubes [11] and piezopackages coupled with one-co-ordinate carriages suspended on elastic guides [12] with lever systems [13].
It is difficult to foresee the prospects of development of this or that direction, however any new solution should be better patented in an "umbrella" form. For example, in order to increase the umbrella covering of a patent the following elements were introduced in a micropositioner [14] with a lever system: inserts minimizing the thermodrift of the carriages; strain sensors eliminating nonlinearity, hysteresis and creep of piezoceramic; capacitor and interferential sensors of linear movements reducing the movement error of the carriages.
Also developed were rather exotic piezoscanners and micropositioners on rectangular piezobimorphs [15], however they got only limited distribution because of their insufficient rigidity. Positioners on the basis of round piezobimorphs [16] were offered, but they were not developed further because of their small movements. Besides, absence of dependent points in the formulas of inventions, in particular, descriptions of the sensors of the main and nonfunctional movements, limited the potentials of the devices.
It is necessary to point out, that employment of measuring transducers of various parameters is useful for improvement of the characteristics of many devices and increase the chances of obtaining a patent. According to foreign patent lawyers, the main drawback of the Russian applications is small volume of the so-called "meat". An idea and two or three distinctive signs can be of a breakthrough character, but usually the number of the dependent points in an invention formula is insufficient. This often does not allow us to obtain patents on interesting solutions, because an expert will find references to separate signs of the formula of the invention, which becomes simpler due to new databases and improvement of the patent search.
Getting back to the tube piezocsanners, which got basic development and are more often used in the probe microscopy than other systems, we should point out that some products were patented, which due to complex bends ensured an increased range of movements and preserved its flatness [17, 18]. Nevertheless, due to their insufficient umbrella character a patent was obtained [19], in which original polarization and connection of piezotubes were applied, and also external drives, which extended the opportunities of the device.
Also a patent was obtained [20], in which the module of the axial movement of a piezoscanner was coupled with the elastic guides, minimizing its nonfunctional movements. The piezoceramic scanners were combined with the known mechanical devices, which gave an essential technical effect with minimal costs. A tube three-co-ordinate piezoscanner [21] was integrated with copies of its functional modules simulating its movements separately by each co-ordinate. These simulators were supplied with sensors and had improved characteristics, at that, operation of the basic scanner was adjusted depending on their functioning.
It would also be appropriate to discuss examples of a bypass of an original patent. In 1990s an inertial stepper motor was developed, based on a piezoceramic package coupled with two guides [22], and a device on its basis [23]. That motor (fig.2) contained platform 1, on which carriage 2 was installed, tightened to the platform by a cover plate 3 with spring 4.
On carriage 2 piezopackage 5 was fixed connected with massive element 6 installed on supports 7 with a possibility of sliding in relation to platform 1. Sawtooth voltage was supplied to piezopackage 5. Smooth front 9 moved massive element 6 by co-ordinate X in the positive direction. At that, due to friction carriage 2 remained on its place.
In case of a voltage jump 10 (abrupt front) carriage 2 slipped on platform 1 by co-ordinate Х also in the positive direction. This principle of movement has been known for a long time, nevertheless, due to optimization of the design a patent [22] was obtained and it had a rather wide umbrella.
A decision was taken to bypass this patent [22], which became possible due to setting a task of removal of the rest of the gas between the rubbing surfaces of platform 1 (fig.3) and carriage 2 [24].
Pumpdown and freezing decreased the low-temperature sealing of carriage 2 on platform 1. Besides, the carriage was tightened to the platform by flat spring 8 fixed on bracket 9 and coupled with adjustable tightening 4 and stabilizing the movement of the carriage due to exclusion of the nonfunctional movements of cover plate 3 on co-ordinate Х. (Sawtooth voltage was supplied to piezopackage 5). In patent [25] in addition to a slightly changed system of flat springs and movement sensors introduced in it, a start module (not shown in fig.3) was added, excluding a low-temperature sealing.
Analysis of patenting of the technologies with application of piezoceramics suggests a conclusion that the main principle of development of hi-tech patents is often ignored: minimization of the first independent point and an umbrella character of the invention formula. In this case a bypass of the umbrella patents is possible, if a new task is set.
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