In a wide variety of applications, a method of aligning two or more surfaces or members may be needed. Sometimes this alignment is to be very precise, as in nanotechnology applications. In other cases, the alignment needed is on a macroscopic scale.
While aligning members is so frequently needed in many diverse applications, many existing methods for aligning two members, such as optical alignment systems, may not have the desired speed or accuracy. Many existing methods of aligning two members may also not easily scale as needed by the variety of possible applications.
The accompanying drawings illustrate various embodiments of the principles described herein and are a part of the specification. The illustrated embodiments are merely examples and do not limit the scope of the claims.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.
Due to the high cost of existing alignment techniques, it would be desirable to provide a low-cost method for facilitating automatic surface alignment in a variety of applications. A significant factor in reducing the cost of alignment may involve eliminating the need for a skilled operator. Instead of involving a skilled operator, it may be beneficial and more efficient to provide a system in which surfaces automatically align themselves according to desired specifications.
To accomplish the above and other goals, the present specification discloses illustrative systems and methods of automatically aligning the surfaces of two mating members. The systems and methods may utilize correlated patterns of material disposed on the mating surfaces of the members. The patterns may be configured to orient the mating surfaces into a desired alignment as the members are brought together.
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present systems and methods. It will be apparent, however, to one skilled in the art that the present systems and methods may be practiced without these specific details. Reference in the specification to “an embodiment,” “an example” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least that one embodiment, but not necessarily in other embodiments. The various instances of the phrase “in one embodiment” or similar phrases in various places in the specification are not necessarily all referring to the same embodiment.
The principles disclosed herein will now be discussed with respect to illustrative system and methods.
Referring now to
It will be further understood that while the first and second members (101, 103) illustrated in the examples of the present specification and its accompanying figures may be geometrically simple for the purpose of clarity, any suitable shape and/or material for mating members may be used in conjunction with the principles described in the present specification. For example, the principles of the present specification may be applied to the alignment of mating members in the fabrication and/or operation of nano-devices or other nanotechnology-related applications.
As shown in
As used herein and in the appended claims, the term “correlated pattern” will refer to a pattern that is correlated with a complementary pattern on an opposite member, the correlation resulting from convolution of a random or pseudo-random pattern with a spread function as described herein.
These correlated patterns of material (109, 111) on the mating surfaces (105, 107) are configured to match or complement each other such that when the first and second members (101, 103) are brought together, the first and second mating surfaces (105, 107) are oriented into a desired alignment by the matching of the complementary, correlated patterns.
The material(s) used to create the correlated patterns of material (109, 111) on the mating surfaces (105, 107) may create an array of bipolar elements within the correlated patterns of material (109, 111) such that attractive and/or repulsive forces between the correlated patterns of material (109, 111) in each of the mating surfaces (105, 107) may be used to create an inherent propensity between the correlated patterns of material (109, 111) to be aligned in a certain way.
As shown in
To facilitate the alignment of the two members, the bipolar elements in the pattern may have some correlation rather than a purely random pattern. Where this is the case, the bipolar elements will exert a force toward the proper registration of the two patterns even before that desired registration is completely achieved.
As shown in
Convolution (151) is a known mathematical operation that takes two functions f and g and produces a third function that, in a sense, represents the amount of overlap between f and a reversed and translated version of g. The convolution of f and g is written f*g and can is defined as the integral of the product of the two functions after one is reversed and shifted. Thus, convolution (151) is a particular kind of integral transform as will be described in more detail below.
The spread function (152) has a single maximum or minimum, with a curve directed to the extremum from both directions. Consequently, this property of moving to an extremum will be imparted to the function resulting from the convolution (151). The extremum will represent that point at which the complementary patterns on the mating surfaces of the members being aligned are properly registered.
In the following equation, the random function (150) is f, and the spread function (152) is g. Then, for example, by convolution theorem, the function (152) resulting from the convolution (151) is represented by p.
p=FT(R*S)
where FT is the Fourier transform operator;
R is FT(f); and
S is FT (g).
The function p (153) resulting from the convolution (151) can be unique, because it is based in part on the random function (150). It is also deterministic in that complementary patterns of bipolar elements corresponding to the convolved function (153) will exert a mutual force on each other corresponding to the extremum of the spread function (152) which is also the alignment at which the patterns are properly registered.
The function p (153) is then used to generate the two correlated complementary patterns that are formed on the two members to be aligned. For example, the mean value of the function (153) is determined. Then, depending on the number of individual elements desired in the final pattern, the function (153) is divided into a corresponding number of increments. For each increment, an average or representative value is determined which is then compared to the mean of the function (153). If the average or representative value is at or above the mean of the function, a first bipolar element is chosen for that portion of the pattern. If the average or representative value is below the mean of the function, the second bipolar element is chosen instead for that portion of the pattern. This process continues until each increment of the function (153) has been quantized into one or the other of the bipolar elements being used to form the pattern. The result is a pattern that is formed on one of the two members or mating surfaces to be aligned.
The pattern for the other of the two members or mating surfaces is then the complement or exact opposite of the pattern produced by quantizing the function (153). This complementary pattern is then formed on the other of the two members or mating surfaces.
Consequently, using the method illustrated in
Referring now to
Due the fact that opposite magnetic poles attract each other, the correlated patterns of material (205, 207) may be configured to complement each other. In other words, each of the first and second members (201, 203) may have a correlated pattern that is the exact opposite of the pattern on the other member. Due to the non-repeating nature of the correlated patterns of material (205, 207), there may be only one stable position in which each portion (209) is closest to another portion (209) having an opposite magnetic polarity. When the first and second members (201, 203) are not in a desired alignment state, as shown in
The portions (209) of the correlated patterns (205, 207) may be magnetized during fabrication of the first and second members (201, 203) by a direct writing process similar to that used in writing digital data to a hard disk. In such a writing process, an electromagnetic head is passed over each of the portions (209) of the pattern and exerts a magnetic field over each portion (209) determined by the desired polarity of each of the portions (209). This method may be particularly useful in high-security applications, where unique patterns prevent the unauthorized use of the two members (201, 203). For example, in some cases, one of the members (201, 203) may be a component in a piece of manufacturing equipment, and another of the members (201, 203) may be a component of a device manufactured by the process.
As described herein, each complementary pattern can be unique because each can be based on a unique random function. The uniqueness of each set of complementary correlated patterns can prevent the alignment of two parts not designed for each other. If one accidentally or intentionally tries to align two parts, each having a correlated pattern, but where the two patterns are not complementary to each other, there will be no matching or settling of the patterns into an aligned state. Consequently, the error of trying to align to parts not intended for each other can be quickly realized.
Additionally, unique complementary correlated patterns (205, 207) used on the first and second members (201, 203) may prevent or deter a user from attempting to utilize one of the members (201, 203) with unauthorized manufacturing equipment or to manufacture an unauthorized device using one of the members (201, 203). In such cases, a uniquely written correlated pattern (205, 207) may be used as a “lock-and-key” approach to security.
In other embodiments, security and unique patterning may not be very significant concerns. In such embodiments, the portions (209) of the correlated patterns (205, 207) may be magnetized by direct contact to a magnetic stamp having the desired pattern. This may be performed in a somewhat similar manner to the way a stamp is used in imprint lithography. This method may be preferable when low-cost mass production capabilities are desired.
At least one of the first and second members (201, 203) may include a thin coating (211) disposed over its corresponding mating surface to facilitate the smooth sliding of the mating surfaces against each other to reach the desired alignment. This coating (211) may include a polymer substance, such as Teflon, or any other lubricating substance as may fit a particular application. The coating (211) may be disposed over the at least one mating surface using any suitable technique, as may fit a particular application.
However, the coefficient of friction between the first and second members (201, 203) should be non-zero. Some friction between the first and second members (201, 203) will help control lateral movement of the members (201, 203) relative to each other and facilitate the alignment of the members and the matching of complementary correlated patterns, irrespective of the bi-polar material used to form the patterns.
The coefficient of friction between the first and second members (201, 203) relates the lateral force on the members to the attractive force between the complementary patterns. The attractive force between the complementary patterns is typically normal to surfaces of the members (201, 203) and the lateral force and movement of the members (201, 203). Specifically, the coefficient of friction multiplied by the normal force equals the frictional force. Consequently, a non-zero coefficient of friction provides a lateral frictional force that helps achieve alignment. For example, as the first and second members move with respect to each other, for example, sliding over each other, some amount of friction between the members will thus help facilitate the complementary patterns from sliding past each other, causing the members to slow and stop with the desired alignment where the complementary patterns are matched.
The coefficient of friction can be selected or controlled by the selection of surface materials or coatings for the first and second members (201, 203). The coefficient of friction can also be controlled by providing a texture on the surfaces of the first and second members (201, 203).
Referring now to
The correlation function values C(x) indicate the degree of similarity between the total magnetic fields produced by the two members (201, 203,
Since opposite poles in magnets attract, the most stable position magnetically for the correlated magnetic patterns (205, 207,
The correlation functions (301, 303) created by different correlated patterns (205, 207,
As shown in
In order to achieve the goal of creating a non-deterministic correlated pattern (205, 207,
Referring now to
Hydrophilic materials tend to attract other hydrophilic materials and repel hydrophobic materials. Likewise, hydrophobic materials tend to attract other hydrophobic materials and repel hydrophilic materials. Due to this property, the correlated patterns (405, 407) of the first and second members (401, 403) may be configured to match each other. In other words, each of the first and second members (401, 403) may have exactly the opposite correlated pattern as the other member when viewed in cross-section.
Similar to the magnetic embodiment of
The hydrophilic and hydrophobic portions (409, 411) of the correlated patterns (405, 407) may be created on the mating surfaces of the first and second members (401, 403) using a variety of techniques. For example, the hydrophilic and hydrophobic portions (409, 411) of the correlated patterns (405, 407) may be created on the mating surfaces of the first and second members (401, 403) by using conventional photolithography or imprinting techniques to deposit hydrophilic and hydrophobic chemicals on the surfaces as needed to form the complementary patterns.
Referring now to
The correlation function values C(x) indicate the degree of similarity between the total chemical characteristics of the correlated patterns (405, 407,
Since mutually hydrophilic portions (409,
As described previously, the correlation functions (501, 503) created by different correlated patterns (405, 407,
As shown in
As shown in
Referring now to
Additionally, in some embodiments, a small mechanical oscillator (613) may be disposed on at least one of the first and second members (601, 603) near at least one of the correlated patterns (605, 607) to prevent the mechanical features (609, 611) of the correlated patterns (605, 607) from binding to each other prior to obtaining the desired alignment. Any suitable mechanical oscillator (613) may be used according to a particular application, including, but not limited to, piezoelectric oscillators, springs, pendulums, and the like.
The mechanical features (609, 611) in the correlated patterns (605, 607) may be formed in a material deposited on the mating surfaces of the two members (601, 603) and molded or embossed according to the desired correlated patterns (605, 607). In some embodiments, a soft deformable polymer or other material may be deposited on the mating surfaces of the two members (601, 603) and embossed according to the desired correlated pattern.
Referring now to
Referring now to
Referring now to
The arrows in
Referring now to
An actuator (1013) may be configured to impart mechanical motion to at least one of the first and second members (1001, 1003) such that the mating surfaces (1009, 1011) of the first and second members (1001, 1003) are brought together. As the first and second mating surfaces (1009, 1011) are brought together, the correlated patterns (1005, 1007) on the mating surfaces (1009, 1011) may be configured to orient the mating surfaces (1009, 1011) according to a desired alignment.
In some embodiments, a plurality of actuators (1013) may be used to bring the first and second mating surfaces (1009, 1011) together. Any suitable actuator may be used, as may fit a particular application. Examples of suitable actuators include, but are not limited to, mechanical actuators, electric motors, hydraulic actuators, and combinations thereof.
Referring now to
In some embodiments, deposition (steps 1101, 1103) of correlated patterns of material may include selectively magnetizing portions of material deposited on the mating surfaces. In other embodiments, the deposition (steps 1101, 1103) of the correlated patterns of material may include selectively embossing complementary mechanical structures into a deformable layer on each of the mating surfaces. In still other embodiments, the deposition (steps 1101, 1103) of the correlated patterns of material may include selectively depositing patterns of hydrophilic and hydrophobic chemicals.
The first and second mating surfaces may then be oriented (step 1105) in a desired alignment by bringing the mating surfaces together. As described herein, the patterns will then exert or respond to forces that bring the patterns, and consequently the members on which they are respectively disposed, into the desired alignment with each other.
As will be appreciated by those skilled in the art, the principles described herein may also be applied to a variety of security applications. For example, a lock may consist of a member with a correlated pattern as described herein. The lock is actuated or “opened” when a member, i.e., a key, bearing the corresponding correlated pattern is aligned and matched with the pattern on the lock member according to the principles described herein. Various different means and methods which will be apparent with the benefit of this disclosure, may be used to detect when the correspondingly patterned member is mated with the first or “lock” member.
The preceding description has been presented only to illustrate and describe embodiments and examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and-variations are possible in light of the above teaching.
The present application claims priority from provisional application Ser. No. 61/040,018, filed Mar. 27, 2008, the contents of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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61040018 | Mar 2008 | US |