GB2626604A

GB2626604A - Sample support system

Info

Publication number: GB2626604A
Application number: GB2301289.1A
Authority: GB
Inventors: Stanescu Sorin-Laurentiu; Vilain Sebastien; Ivan Thomas Chaeron Urwin Kenelm; Soori Zagros; Li Lin; Guo Wei
Original assignee: Lig Nanowise Ltd
Current assignee: Lig Nanowise Ltd
Priority date: 2023-01-30
Filing date: 2023-01-30
Publication date: 2024-07-31
Also published as: GB202301289D0

Abstract

A support system 1 for a microscope comprises a base 5, sample platform 2, and a displacement mechanism 6 attached to the base and sample platform, the mechanism operable to vary the displacement between the base and sample platform via an interacting coil 7 and magnet 8 assembly (e.g. an electromotive voice coil connected to a user-actuatable control unit and power supply). This may reduce impact force on a lens of the microscope and/or sample/platform if they collide, and reduce breakage and/or misalignment of the microscope. Multiple of the mechanisms may be provided symmetrically underneath the sample platform, they may be telescopic and may be biased (e.g. via a spring) to urge the sample platform towards the base. A guide member 9, 10 may extend perpendicularly from the base, so the platform remains parallel to the base. Sensors 12, 13 may output a platform position to the control unit and the platform position adjusted via the control unit.

Description

SAMPLE SUPPORT SYSTEM Technical Field of the Invention The present invention relates to a sample support system. Particularly, but not exclusively, the present invention relates to a sample support system for use with microsphere lens based microscopes and other near field optical microscopes.

Background to the Invention

M icrosphere lens based microscopes are well known in the art. Microsphere lens based microscopes typically comprise a standard microscope system, wherein the microscope comprises a microsphere lens. In some cases, a microsphere microscope may comprise an array of microspheres within the microsphere lens. Microsphere lenses can be difficult to manufacture and are rather delicate and easily damaged.

A microsphere lens allows for super resolution imaging. However, a known challenge of super-resolution imaging using microsphere lenses is that the working distance is relatively small. Typical working distances for a microsphere lens is around 15 500 nm for 'thy' imaging, and between 2-10 pm for immersion techniques.

Naturally, this working distance is small, and therefore users can inadvertently impact the microsphere lens with the sample/sample platform when adjusting the distance between the sample and lens during focusing and observation of different locations.

Conventional sample platforms and their support systems are arranged such that the sample platform is substantially rigid and held fixed at a set distance from a base. This means that impacts between the sample/sample platform and the lens often damage the lens.

One example of a microsphere lens assembly is described in WO 2019/002873A1. This discloses a microsphere lens assembly comprising: a base lens; a microsphere lens and a column of optically clear material extending from a front. surface of the base lens to the microsphere lens. This is particularly advantageous as this allows for the microsphere lens to he accurately positioned at a fixed distance from the base lens and aligned to the optical axis in use for optimal performance. The fixing of the microsphere lens in position also provides for a simple and robust construction of the attachment. Whilst this arrangement is more robust than other arrangements, this is still vulnerable to breakage during impacts with the sample/sample platform.

In other arrangements, the microsphere lens is attached to the base lens using a specialised adaptor. This is less ideal, as the adaptor cannot guarantee the alignment of the microsphere in the optical axis. Further, such adaptors are often delicate, and thus highly prone to breakage and/or misalignment due to impacts with the sample/sample platform.

It is an object of the present invention to at least partially overcome and/or mitigate the above illustrated issues with known sample support systems.

Summary of the Invention

According to a first aspect of the present invention, there is provided a support system for a microscope sample comprising: a base, a sample platform, and at least one displacement mechanism attached to the base and sample platform, the or each displacement mechanism being operable to vary the displacement between the base and sample platform, wherein the or each displacement mechanism comprises an interacting coil and magnet assembly.

This support system allows for the sample platform to be supported with a surplus force which is much smaller force than conventional support systems. This significantly reduces the force required for an impact to move the sample platform. This allows accidental impacts between the sample/sample platform and the lens to move the sample platform, which reduces the likelihood of lens breakage and/or misalignment, and also reduces the severity of any such impacts. The use of one or more coils is beneficial as each coil converts electrical signals directly into a linear magnetic force, providing much higher purity of motion compared to DC motors (which require separate drivetrains, such as belts or gears). This provides quicker, more accurate movement with better repeatability, in addition to the benefits laid out above.

The or each displacement mechanism may be operable to vary the displacement between the base and the sample platform between Omm and 20mm Preferably, the or each displacement mechanism may be operable to vary the displacement between the base and the sample platform between Om m and 10m m. Most preferably, the or each displacement mechanism may be operable to vary the displacement between the base and the sample platform between Ornm and 6.3mm The or each magnet assembly may comprise a single magnet arranged to be received inside the corresponding coil. Additionally or alternatively, the or each magnet assembly may be arranged such that a coil is received within the corresponding magnet assembly. In such embodiments, the or each magnet assembly may comprise a single hollow, tubular magnet in which the corresponding coil is received. The or each magnet assembly may comprise a permanent magnet. The or each magnet may comprise an electromagnet. The or each coil and magnet assembly may be a voice coil.

For the or each displacement mechanism, the or each coil may be attached to the base, and the or each magnet assembly may be attached to the sample platform. Alternatively, the or each coil may be attached to the sample platform and the or each magnet assembly may be attached to the base.

In embodiments where there is a single displacement mechanism, the displacement mechanism may be attached to the sample platform such that the displacement mechanism is positioned directly beneath the sample.

There may be two, three, four, or any suitable number of displacement mechanisms. In embodiments with more than one displacement mechanism, the 20 respective coils and magnets therein may be identical, such that the displacement mechanisms are also identical.

hi embodiments where there are multiple displacement mechanisms, the displacement mechanisms may be arranged such that they are symmetrical underneath the sample platform. The skilled person will understand that this could occur in many suitable arrangements.

For example, the displacement mechanisms may be placed in each corner of the sample platform. Alternatively, the displacement mechanisms may be placed at the mid-point of each side of the sample platform. Alternatively, the displacement mechanisms could be placed in a manner such that each displacement mechanism is equally spaced from its neighbouring displacement mechanism/s.

The or each displacement mechanism may comprise one or more telescopic portions.

The support system may comprise a biasing mechanism. The biasing mechanism may be operable to impart a biasing force on the sample platform.

Particularly, the biasing force may be operable to urge the sample platform towards the base. In some embodiments, the biasing force may be provided by the weight of the sample platform. In alternative embodiments, the biasing force may be provided by a biasing member. In such embodiments, the biasing member may be a spring.

The support system may comprise a guide mechanism. The guide mechanism 10 may comprise at least one guide member. The or each guide member may be arranged so as to ensure the sample platform remains parallel with the base whilst the displacement between the sample platform and base is varied.

The at least one guide member may extend perpendicularly from the sample platform towards the base. The guide mechanism may comprise at least one guide member extending perpendicularly from the base towards the base towards the sample platform. The or each guide members may be arranged such that one of the guide members is received in the other guide member in a close sliding fit.

The base may comprise one or more arms which extend perpendicularly from the base. The or each arm may extend from the base a distance further than the maximal displacement from the sample platform from the base. The or each arm may comprise a lip which extends over the sample platform. Together the or each arm and lip may serve as a stop for the sample platform. This allows the arms to limit the distance the sample platform can be displaced from the base.

The or each coil may be connected to a power supply. In embodiments where 25 the or each magnet is an electromagnet, the or each magnet may be connected to a power supply.

The power supply may be integral to the support system. In such embodiments, the power supply may be a battery.

Alternatively, the power supply may be a connector to connect the support system to an external power source. In such embodiments, the power supply may be a mains connection.

The power supply for the or each coil and/or magnet may be connected to a control unit. The control unit may be operable to control the voltage and/or current provided by power supply to the or each coil and/or magnet.

The support system may comprise one or more sensors. The or each sensor may be operable to detect the position of the sample platform. In particular, the or each sensor may be operable to detect the position of the sample platform relative to the base.

In embodiments where there the base comprises one or more arms comprising a stop, the or each sensor may be operable to detect the position of the sample platform in relation to the or each stop.

The or each sensor may be connected to the control unit. The or each sensor may be operable to output signals comprising information about the position of the sample platform to the control unit.

The control unit may be connected to an output unit. The output unit may be operable to output information about the position of the sample platform. This may serve to inform a user of the position of the sample platform. The output unit may be operable to output a visual and/or audio signal. The visual signal may comprise a flashing light. The visual signal may comprise a message displayed on a display unit.

The audio signal may comprise a buzzer. The audio signal may comprise a repeating alarm.

The or each sensor may be operable to output a signal to the control unit. The signal may cause the control unit to output information from the output unit. This sensor may comprise a simple press-switch. The press-switch may be actuated by a protrusion extending from the sample platform towards the base.

A sensor may be operable to inform the user that the sample platform is too far from the base. This sensor may comprise a pair of electrical contacts. One of the contacts may be placed upon the sample platform, and the other may be placed upon a 30 sensing arm extending from the base. The sensing arm may comprise a lip which extends above the sample platform. The contact may be placed upon the sensing arm such that it is opposite the contact upon the sample platform. The respective contacts upon the sample platform and sensing aim may serve to contact each other when the sample platform reaches a predetermined height. In such embodiments, contacts may close a sensor circuit and serve to send a signal to the output unit. In embodiments where the bases comprises on or more arms and lips which from a stop, the arms and lip may be the sensing arm.

The control unit may be operable in response to a user actuablc input. The user actuable input may comprise an interface which outputs control signals via which the control unit can vary the displacement between the sample platform and base.

Additionally or alternatively, the control unit may be operable to automatically vary the displacement between the sample platform and base.

According to a second aspect of the present invention, there is provided a microscope comprising the support system of the first aspect of the present invention.

The microscope of the second aspect of the present invention may comprise any of the optional features of the first aspect of the present invention as desired or as required. The microscope may comprise a microsphere lens.

Detailed Description of the Invention

hi order that the invention may be more clearly understood one or more 20 embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a cross-section view of a sample support system.

Figure 2 is a cross-section view of a microscope comprising a sample support system.

Figure 3 is a block diagram showing the control components of the sample support system.

Figure 4 is a photograph of a coil and magnet assembly in a first and second state.

Turning to Figure 1, there is provided a sample support system I. The system 1 comprises a sample platform 2. The sample platform 2 has a substantially planar surface 3 configured to hold a sample 4 for examination by a microscope (not shown). Conventional sample fixing attachments (not shown) are provided upon the substantially planar surface 3 to hold the sample 4 in place. The sample platform 2 is attached to a base 5 via a pair of displacement mechanisms 6. The base 5 comprises a substantially planar surface which is parallel to the substantially planar surface 3 of the sample platform.

Each displacement mechanism 6 has an interacting coil 7 and magnet assembly. The coils 7 of the displacement mechanisms 6 are identical to one another. The coils 7 are each attached to the base 5 such that the axis of each coil 7 is perpendicular to the base 5.

In this embodiment, the magnet assembly of each displacement mechanism 6 is a permanent magnet 8, The magnets 8 of the displacement mechanism 6 are identical to one another. The magnets 8 are attached to the sample platform 2, such that they extend perpendicular away from a lower surface of the sample platform 2.

The coils 7 and magnets 8 are each arranged on the base 5 and sample platform 2 (as applicable) such that the coils 7 and magnets 8 interact with one another when the sample support system 1 is assembled.

The coils 7 are connected to a power supply (not shown). The power supply is connected to a control unit (not shown). The control unit is operable to control the power supply so as to vary the current supplied to the coils 7. A current being supplied to each coil 7 produces an electromotive force in each coil 7, which acts upon the magnets 8. This enables the sample platform 2 to be moved towards and away from the base 5. The displacement between the sample platform 2 and base 5 is thus variable and controlled by the current supplied to the coils 7.

hit his specific embodiment, the resistance of each coil is 1.9 a with an inductance of 167 pH.

The system 1 has a guide mechanism which serves to guide the sample platform 2 when in motion. The guide mechanism ensures the substantially planar surface 3 of sample platform 2 and base 5 are parallel to one other throughout the range of motion of the sample platform.

The guide mechanism is formed of a pair of base guide members 9 and corresponding platform guide members 10. The pair of base guide members 9 and platform guide members 10 are positioned symmetrically either side of substantially planar surface 3 of the sample platform 2.

The base guide members 9 each comprise a protrusion which extends perpendicularly away from the base 5 in the direction of the sample platform 2. The base guide members 9 are elongate and annular, to form a tube extending perpendicularly from the base 2 in the direction of the sample platform.

The platform guide members 10 each comprise a protrusion which extends perpendicularly away from the lower surface of the sample platform 2 in the direction of the base 5. The platform guide members 10 are each elongate rods and have a diameter such that they can be received with the annulus of the base guide members 9 in a sliding fit.

The respective guide members 9,10 are arranged on the sample platform 2 and base 5 such that the platform guide members 10 are slidably received within the base guide members.

The base 5 comprises a pair of arms 11. An arm 11 is situated on either side of the sample platform 2. Each arm 11 comprises an elongate protrusion extending perpendicularly from the base 2. At the free end of each arm 11, there is provided a lip which extends over sample platform 2. The lip of each arm 11 serves as a stop for the sample platform 2, in the event that a user (or the control unit) attempts to move the sample platform 2 too far from the base 5.

A first sensor 12 is provided on one of the arms 11. The sensor 12 comprises two parts 12a,12b. One part 12a is placed upon the sample platform 2, and the other 12b on the lip of the arm 11. The two parts 12a,12b are placed opposite each other, such that they contact each other when the sample platform 2 reaches a sufficient displacement from the base 5.

A second sensor 13 is provided on the base 5. The sensor 13 is a press-switch sensor, which is actuated by the sample platform 2 as the sample platform 2 approaches the base 5.

The sensors 12, 13 are each connected to the control unit. Each sensor 12,13 is operable to output signals to the control unit. The control unit is operable to control the current supplied to the coils 7 in response to the output of the sensors 12,13. This allows detection of the position of the sample platform 2 and allows a user and/or the control unit to cease the motion of the sample platform 2 and thereby prevent collisions between the sample platform 2 and the arms 11, or between the sample platform 2 and base 5.

Turning to figure 2, there is provided a microscope 21. In this embodiment, the microscope has a microsphere lens 22, though the skilled person will understand that.

other conventional lenses can be used. The microscope 21 has a sample support system 1 as described above.

Turning to figure 3, there is shown a block diagram of the key control components of a system according to the present invention. The system comprises a control unit 101 which is connected to a user actuable input 102. The user actuable input 102 is operable to control the control unit 101 using control signals. A user is able to control the user actuable input 102 and hence the control unit 101 via a user interface 103.

The control unit 101 is operable to control a power supply 104, which is operable to supply current to the coils 7 of the system 1.

The control unit 101 is also operably connected the sensors 12,13 of the system.

The sensors 12,13 are each operable to output signals to the control unit 101.

An output unit 105 is operably connect to the control unit 101. The output unit 101 is operable to inform a user of the displacement between the base 5 and the sample platform 2. In this embodiment, the output unit has a display unit 106 and a buzzer 107.

The display unit 106 is operable to display a visual message to a user when either of the sensors 12,13 output a signal to the control unit 101. The buzzer 107 is operable to sound an alarm to a user when either of the sensors 12,13 output a signal to the control unit 101.

In use, a user mounts a sample 4 to the substantially planar surface 3 in the conventional manner. The user then, via the user interface 103, control unit 101 and power supply 104, supplies a current to the coils 7. The current in the coils 7 generates a electromotive force. The electromotive force generated by the coils 7 acts upon the magnets 8 and causes them to move away from the coils 7 and hence base 5. The guide mechanisms 9 ensure the sample platform 2 and hence substantially planar surface 3 and sample 4 are parallel to the base 5. The user can, via the user interface 103, vary the power supplied to coils 7, and thereby vary the displacement between the sample platform 2 and base 5. This allows the user to situate the sample 4 in the required position to perform the microscopic analysis of the sample.

hi the event that the user inadvertently attempts to move the sample platform 2 too far from the base 5, the two parts 12a,12b of the sensor 13 contact each other. The sensor and a message is displayed on the display unit 106, and the buzzer 107 sounds an alarm, informing the user of the sample platform's 2 position. In the event that the user attempts to move the sample platform 2 yet further from the base, the lip of each arm 11 serves as a stop, to prevent any such motion of the sample platform 2.

IS In the event that the user inadvertently attempts to move the sample platform 2 towards the base 5 in a manner that will cause a collision between the sample platform 2 and base 5, the sensor 13 is actuated. The sensor 13 outputs a signal, and a message is displayed on the display unit 106, and the buzzer 107 sounds an alarm, informing the user of the sample platform's 2 position. In the event that the user attempts to move the sample platform 2 yet further from the base, the lip of each arm 11 serves as a stop, to prevent any such motion of the sample platform 2.

As discussed above, the system 1 allows for the sample platform 2 to be supported with a minimal surplus force. Therefore, in the event of a collision between the lens 22 and sample platform 21, the sample platform 2 is more easily moved. This /5 allows impacts between the sample 4/sample platform 2 and the lens 22 to move the sample platform 2 towards the base 5. This reduces the likelihood of lens 22 breakage and/or misalignment due to any such impacts Turning to figure 4, there is shown an exemplary coil and magnet assembly as comprised in the or each displacement mechanism 6. The magnet 8 is a hollow, tubular permanent magnet, and sits around the coil 7. When current is passed through the coil 7, an electromotive force is generated, which acts upon the magnet 8. This allows the

I I

position of the magnet 8 relative to the coil 7 to be varied through the application (and variation) of current to the coil 7.

In a first state A, where there is no current applied to the coil 7, the coil 7 and magnet 8 arc at their minimal displacement. In this state, there is no displacement between the coil 7 and magnet 8. In a second state B, where a current has been applied to the coil 7, there is displacement between the coil 7 and magnet 8. The skilled person will understand the coil and magnet assemblies of this type (such as voice coils) are well known in the art, and therefore many different types of coil and magnet assemblies are suitable for use in the support system of the present invention.

The one or more embodiments are described above by way of example only.

Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

CLAIMS1. A support system for a microscope sample comprising: a base, a sample platform, and at least one displacement mechanism attached to the base and sample platform, the or each displacement mechanism being operable to vary the displacement between the base and sample platform, wherein the or each displacement mechanism comprises an interacting coil and magnet assembly.
2. A support system as claimed in claim I wherein the or each magnet assembly comprises a single magnet arranged to be received inside the corresponding coil.
3. A support system as claimed in either claim 1 or 2 wherein the or each magnet assembly is arranged such that the coil is received within the magnet assembly.
4. A support system as claimed in any preceding claim wherein the or each magnet assembly comprises a permanent magnet.
5. A support system as claimed in any preceding claim wherein the or each coil is attached to the base, and the or each magnet assembly is attached to the sample platform.
6. A support system as claimed in any preceding claim comprising multiple displacement mechanisms.
7. A support system as claimed in claim 6 wherein the displacement mechanisms are arranged such that they are symmetrical underneath the sample platform.
8. A support system as claimed in any preceding claim wherein the or each displacement mechanism comprises one or more telescopic portions.
9. A support system as claimed in any preceding claim wherein the support system comprises a biasing mechanism operable to impart a biasing force on the sample platform to urge the sample platform towards the base.
10. A support system as claimed in any preceding claim comprising a guide mechanism.
11. A support system as claimed in claim 10 wherein the guide mechanism comprises at least one guide member extending perpendicularly from the base towards the base towards the sample platform.
12. A support system as claimed in claim 11 wherein the or each guide member is arranged so as to ensure the sample platform remains parallel with the base whilst the displacement between the sample platform and base is varied.
13. A support system as claimed in any preceding claim wherein the or each coil is connected to a power supply.
14. A support system as claimed in claim 13 wherein the power supply for the or each coil is connected to a control unit.
15. A support system as claimed in claim 14 wherein the control unit is operable to control the voltage and/or current provided by power supply to the or each coil.
16. A support system as claimed in any preceding claim comprising one or more sensors.
17. A support system as claimed in claim 16 wherein the or each sensor are operable to detect the position of the sample platform.
18. A support system as claimed in claim 16 or 17 wherein the or each sensor is operable to output a signal comprising information about the position of the sample platform to the control unit.
19. A support system as claimed in any of claims 14 to 18 wherein the control unit is connected to an output unit.
20. A support system as claimed in claim 19 wherein the output unit is operable to output information about the position of the sample platform.
21. A support system as claimed in claim 19 or 20 wherein the output unit is operable to output a visual and/or audio signal.
22. A support system as claimed in any of claims 14 to 21 wherein the control unit is operable in response to a user actuable input.
23. A support system as claimed in claim 22 wherein the user actuable input comprises an interface which outputs control signals via which the control unit can vary the displacement between the sample platform and base.
24. A microscope comprising a support system as claimed in any preceding claim.