Solid state proximity collimation stack and optical measurement system including the same

Abstract

A solid state proximity collimation stack and a system including the solid state proximity collimation stack are described herein. Methods for narrow beam shaping of electromagnetic radiation intended for measurement of fluid samples are also described. The solid state proximity collimating stacks generally include a multi-layer electromagnetic radiation blocking and absorbing component that selectively allows passage of approximately parallel electromagnetic beams.

Description

BACKGROUND

[0001] Optical measurement systems for evaluating liquid sample parameters often incorporate the use of electromagnetic (EM) sources and transduction mechanisms for evaluating the response of EM radiation to the presence of a liquid sample. These systems often require the transformation of a diffuse, distributed, or wide-angle EM radiation source into a focused or collimated beam. Focusing or collimating the EM radiation allows the radiation to be directed at the liquid sample for further reception and analysis.

[0002] Liquid samples of these types of applications are often contained in a vessel that preferentially allows EM radiation to pass through the liquid to perform the measurement. Some such vessels include an array of multiple wells. One of the challenges faced by these types of measurement systems is that the individual wells that hold the liquid sample are often small, typically between 1 mm and 10 mm in diameter. If the EM beam cross-sectional diameter that passes through the liquid vessel is too large, portions of the beam can be scattered, distorted by the shape of the liquid sample surface, or reflected by certain parts of the vessel, to the extent that the measurement is affected. It is therefore advantageous to focus or collimate the EM beam into a thin column before it passes through the liquid sample.

[0003] Conventional methods for achieving this focusing or collimation either use a static array of lenses, where each lens is inherently aligned with a sample, even if multiple samples are to be measured, or a single lens system, where one or more samples can be aligned with a single focused or collimated beam by a robot. Lenses with sufficient precision to form a beam for measuring small volume liquid samples are expensive to manufacture and cost prohibitive. This is especially true for solid state systems that are used to measure multiple samples, which can sometimes require hundreds of individual collimated or focused sources in close proximity to each other.

[0004] Accordingly, there is a need for a solid state method for collimating, narrowing, or otherwise focusing EM radiation in a system for optical measurement of liquids without the use of lenses. This type of system can significantly reduce the cost to the end user and does not require the use of moving parts that can affect reliability. SUMMARY

[0005] In one aspect, a solid state proximity collimation stack for narrow beam shaping of electromagnetic radiation intended for measurement of a fluid sample is described, the solid state proximity collimation stack comprising a plurality of layers of electromagnetic radiation blocking and absorbing components that selectively allow passage of approximately parallel electromagnetic beams.

[0006] In another aspect, a solid state proximity collimation stack is described that further comprises a detection system.

[0007] In another aspect, a solid state proximity collimation stack for measuring a liquid sample is described, the solid state proximity collimation stack configured to measure a sample contained in a microplate well.

[0008] These and other aspects will become apparent from the detailed description that follows, which has been achieved by the inventors' discovery of a new type of solid state proximity collimation stack. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 A cross section of the proximity collimation stack is shown, illustrating electromagnetic reflection, absorption, and the resulting narrow beam formation.

[0010] Figure 2 is an exploded view of the proximity collimation stack.

[0011] Figure 3 A proximity collimation stack is shown aligned with a detection unit and a microplate well.

[0012] Figure 4 is a cross section of the proximity collimation stack in combination with a detection unit and a sample containing vessel loaded with a liquid sample.

[0013] Figure 5 A cross section view of the components within a coupling assembly is shown, the coupling assembly surrounding a sample vessel to be placed within a sample holding component. DETAILED DESCRIPTION

[0014] Exemplary aspects of the present invention are described herein. While the following detailed description contains many specifics for the purpose of illustration, one of ordinary skill in the art will appreciate that changes and alterations in the details described herein can be made without departing from the scope of the application. Accordingly, the following aspects of the present invention are set forth without any loss of generality to, and without imposing limitations on, the claimed invention.

[0015] In one aspect herein, an apparatus is described that includes a combination of an electromagnetic shielding layer and an absorption layer for progressively truncating an electromagnetic (EM) beam into a proximity collimated form by selectively removing emitted light that is not closely aligned with a desired central axis.

[0016] In some aspects, the apparatus is configured such that it can measure EM properties of a liquid sample in a scientific microplate well. In these aspects, the apparatus utilizes one or more EM detectors in combination with the proximity collimation apparatus to measure different parameters of the liquid sample's reaction to applied EM radiation. These parameters can be related to, for example, optical density, fluorescence, luminescence, or other EM reactions to high frequency EM waveforms such as x-rays or gamma rays.

[0017] Figures 1 to 5 The names of the components shown in FIG. 1 are as follows:

[0018] Referring to Figure 1 , a cross-section of a solid-state proximity collimation stack 100 in combination with one or more EM radiation sources (or emitters, e.g., multiple emitters) 200 is shown, the proximity collimation stack comprising: a first electromagnetic absorption layer 101 designed for radial collection of incident emitted light and reflections; a first electromagnetic reflection and selection layer 102 designed for selective passage of incident light waves within a specific angular range; a spacer layer 103 (second electromagnetic absorption layer) designed for radial collection of incident emitted light and reflections, also serving as a spacer element between the first and second reflection and selection layers (102, 104); a second electromagnetic reflection and selection layer 104 designed for selective passage of previously selected light waves within a further specified angular range; and a mechanical clamping layer 105 (e.g., top layer) designed for securing all components in the stack together and allowing component alignment. In some examples, the first electromagnetic absorption layer (101) is referred to as an absorptive beam emitter separation layer. Examples of materials include plastic (101 and 103) and metal (e.g., stainless steel) (102, 104, and 105).

[0019] In another aspect, the first electromagnetic reflection and selection layer (102) is composed of a matrix of digitally adjustable light blocking elements that can be electronically and reversibly configured to form pinholes.

[0020] In another aspect, the second electromagnetic reflection and selection layer (104) is composed of a matrix of digitally adjustable light blocking elements that can be electronically and reversibly configured to form pinholes.

[0021] In another aspect, the solid-state proximity collimation stack is substantially devoid of one or more focusing lenses. Examples of being substantially devoid include lacking focusing lenses.

[0022] In another aspect, both the first and second electromagnetic reflection and selection layers (102, 104) are composed of a matrix of digitally adjustable light blocking elements that can be electronically and reversibly configured to form pinholes.

[0023] In another aspect, the pinhole diameters of the first and second electromagnetic reflection and selection layers (102, 104) are less than or equal to 2 millimeters, and the thickness of the selection layers (102, 104) is less than or equal to 500 micrometers.

[0024] In other aspects, the solid state proximity collimating stack 100 further comprises a cylindrical wall 106 on the spacer layer 103, built from a rough EM-absorbing material, such as a 3D printed surface with an intentionally optically blocking texture or an optically rough texture created using multi-jet fusion or similar technology. In another aspect, the wall 106 is created to have features that collect and absorb EM radiation, such as cavities with slits cut into them for collecting incident light rays, or angular surfaces designed to reflect and collect incident waveforms and / or absorb their emitted energy. Additionally, other techniques can be appreciated by those skilled in the art, such as texturing the surface with sandblasting or laser engraving to create a surface that is absorptive to certain frequencies in the EM spectrum.

[0025] In Figure 2 , an exploded isometric view of an EM solid state proximity collimating stack 100 is shown, mechanically aligned with multiple EM emitting sources (transmitters) 200 mounted on a printed circuit board. This figure shows Figure 1 One example of a mechanical implementation of the cross-sectional component stack shown in is shown in, arranged in an array to emit multiple beams of proximity collimated EM radiation. The beams are first confined by the electromagnetically absorptive cavity 114 and then pass through the electromagnetically transparent pinhole 113, followed by the second electromagnetically transparent pinhole 110. Additionally, Figure 2 Features for assembling and aligning the physical components are shown, including: long side edges 108 and short side edges 107 designed to enable the components in the stack 100 to be co-registered; countersunk holes 109 that allow for accommodating self-aligning fasteners to secure and align the stack components; slot holes 111 for relative alignment of the components in the stack 100; side slots 112 where the components within the stack can be secured and aligned to features including a housing or enclosure; holes 115 in the circuit board designed in a manner to interface and align the circuit board with a mating housing or enclosure.

[0026] Figure 3A exploded cross-sectional isometric view of an EM solid state proximity collimation stack 100 is shown, which is mechanically connected to a plurality of emitters 200 mounted on a substrate layer comprised of printed circuit boards, and aligned with a plurality of EM radiation detection systems 300 mounted on a second printed circuit board, all of which are in turn aligned with an example sample container 400, in this case a commonly used 96 well scientific microplate. Other standard microplates can also serve as the basis for emitter-detection alignment, including but not limited to 6 well, 12 well, 24 well, or 384 well polystyrene microplates. Standard microplates are typically made of polystyrene. Microplates are known in the art, but the microplates used herein can include multiwell plates and / or microtiter plates. Other examples include polycarbonate and glass. The introduction of EM radiation detection systems 300 requires features that enable the detection system to be durably aligned with the stack 100, including: mechanical mounting features, such as threaded holes 302 and registration features, such as pin holes 303. By way of example, alternative (or additional) durable alignment components include: registration rails that utilize a positioning lug in contact with an outer edge; a positioning screw location for incremental adjustment of relative position; and / or a reference surface for interfacing with a positioning pin. Figure 3 Electronic components (e.g., microprocessor, wireless transceiver module, real time clock, etc.) are also shown in Figure 3 but are not numbered in

[0027] Reference is made to Figure 4 , which shows an orthogonal cross-sectional view of a single instance of an arrayed EM emitter system depicted in Figure 3 , which includes a detector 301 durably mounted on a detection system 300; a proximity collimated beam 201 generated by the combination of an EM solid state proximity collimation stack 100 mechanically connected to an EM emitter source (emitter) 200. In this regard, the device is designed such that the detector 301 is positioned to receive an incident EM radiation beam 201 after it has passed through a liquid sample 401 to measure a parameter of the liquid sample. In this instance, it is desirable to narrow the EM beam 201 to the extent that the diameter of the beam does not exceed the size of the detector 301, or be diffracted through the sample-air interface 402 (not shown) such that it would cause the extent of the EM beam to exceed the size of the detector, or be reflected or distorted from the side of the small volume sample container 403.

[0028] Figure 5A cross-sectional view showing an example of the alignment of the previously described components within a coupling assembly 500 around a sample container 506 to be placed within a sample holding component 505. In this example, the components are aligned via dedicated alignment features 504 and permanently attached using permanent fasteners 503. In this example, the upper component 501 of the coupling assembly 500 can be separated from the rest of the assembly to support the insertion and removal of the sample container 506 and then returned to its original configuration using the dedicated alignment features 502.

[0029] It is important to maintain the shape of the EM beam 201 during the liquid parameter measurement for several reasons. First, to make an absolute measurement of a liquid sample parameter, almost all of the EM energy emitted by the EM emission system 200 that is not absorbed or scattered by the sample 401 should be collected by the EM detection system 300. By almost all, it is meant at least 90%, 95%, 99%, 99.5%, and / or 99.9% of the EM energy emitted by the EM emission system 200 that is not absorbed or scattered by the sample 401 is collected by the EM detection system 300. Second, EM energy that is reflected from the container wall 403 or refracted by the liquid-air interface 402 (not shown) can reach adjacent detectors in an arrayed system, which can alter the measurement of the parameter being measured in an adjacent container. Thus, near-collimation of the EM radiation beam 201 represents an important and novel aspect of the development of a solid-state liquid sample parameter measurement system.

[0030] In another aspect, a solid-state near-collimation stack is described, comprising: a. a substrate layer; b. one or more electromagnetic emitters (200) at fixed locations on the substrate layer; c. a first electromagnetic radiation reflecting and selecting layer (102) covering the one or more emitters (200), the first electromagnetic radiation reflecting and selecting layer comprising a material containing one or more electromagnetic transparent pinholes (113) aligned with each emitter to form an emitter-pinhole pair; d. a spacer layer (103) covering the first selecting layer, the spacer layer comprising an optically absorbing or blackbody material and containing a passage in optical alignment with each emitter-pinhole pair; e. a second electromagnetic radiation reflecting and selecting layer (104) configured to cover the spacer layer (103), the second electromagnetic radiation reflecting and selecting layer comprising a material containing an electromagnetic transparent pinhole (110) in optical alignment with each passage in the spacer layer; and, f. a top layer (105).

[0031] In another aspect, the proximity-collimation stack is used for narrow-beam shaping of electromagnetic radiation, intended for measurement of fluid samples.

[0032] In another aspect, each of the one or more electromagnetic emitters in the stack is operable to transmit electromagnetic radiation at one or more wavelengths in the infrared, visible, or ultraviolet spectrum.

[0033] In another aspect, the emitted light exiting the stack is confined to a narrow angular range via reflection and absorption of light outside the range.

[0034] In another aspect, the emitted light exiting the stack is approximately parallel to each other.

[0035] In another aspect, a solid-state system for optical measurement of fluid samples is described, comprising: a. a proximity-collimation stack as described herein; b. a sample-holding component (505) configured to accept one or more fluid samples or a container comprising one or more fluid samples; c. an optical detection system (300) comprising one or more optical receivers (301); and, d. an emitter-detector coupling assembly (500) comprising a rigid frame or a series of interlocking or semi-permanent coupling parts; wherein: each receiver (301) is operable to detect the electromagnetic radiation from at least one of the emitters (200); the sample-holding component (505) is placed or can be configured to place one or more fluid samples in optical alignment with the radiation of at least one emitter, such that the radiation will pass through the one or more samples; and, the coupling assembly (500) temporarily or permanently holds the proximity-collimation stack, the sample-holding component (505), and the optical detection system in persistent alignment, such that at least one of the emitted light of the emitters is in optical alignment with at least one sample, and the emitted light of the emitters passes through the sample to at least one receiver.

[0036] In another aspect, the proximity-collimation stack further comprises: g. an absorbing layer (101) located between the base layer and the first selection layer (102), and containing, for each present emitter, an absorbing column, each column being configured to enclose a corresponding emitter.

[0037] In another aspect, in a solid state system, there is the same number of emitters, first selective layer pinholes, spacer layers, second selective layer pinholes, and optical receivers.

[0038] In another aspect, the number of emitters, first selective layer pinholes, spacer layers, second selective layer pinholes, and optical receivers is 96. Additional examples include 6, 12, 24, and 284.

[0039] In another aspect, in a solid state system, the coupling assembly (500) includes a single rigid housing configured to block interfering electromagnetic emission light from outside the frame or coupling part, but contains an opening for insertion of one or more samples.

[0040] In another aspect, the opening is covered by a cover plate.

[0041] In another aspect, in a solid state system, the coupling assembly includes two rigid housings configured to couple and decouple from each other such that when the housings are coupled, one or more emitters and one or more optical receivers are optically aligned.

[0042] In another aspect, in a solid state system, one housing contains the proximity collimation stack and one housing contains the optical detection system, and when they are coupled, define a sample holding component (505).

[0043] In another aspect, in a solid state system, the two housings are connected by a hinge to form a clamshell configuration.

[0044] In another aspect, a method for optically measuring a fluid sample by passing collimated electromagnetic (EM) radiation through a bore containing the fluid sample is described, the method comprising: a. beam shaping the EM radiation using a proximity collimation stack; b. directing the beam shaped radiation through the fluid sample contained in the bore.

[0045] An example of an optical measurement is a measurement of optical density. Such measurements can be used to perform immunoassays, measure microbial growth, etc.

[0046] In another aspect, the method for optical measurement further comprises: c. detecting the radiation after passing through the sample via an optical receiver.

[0047] In another aspect, the beam shaping comprises the steps of: i. passing electromagnetic radiation from an emitter through a first pinhole; ii. passing the resulting radiation through a spacer layer; and, iii. passing the resulting radiation through a second pinhole; wherein the beam shaped radiation is confined to a narrow angular range via reflection and absorption of light rays outside the range.

[0048] In another aspect, the beam shaping comprises the steps of: i. passing electromagnetic radiation from the emitter through an absorptive beam emitter separation layer; ii. passing the resulting radiation from the emitter through a first pinhole; iii. passing the resulting radiation through a spacer layer; and, iv. passing the resulting radiation through a second pinhole; wherein the beam shaped radiation is confined to a narrow angular range via reflection and absorption of light rays outside the range.

[0049] All references listed herein are incorporated by reference herein in their entirety. Numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the application can be practiced otherwise than as specifically described herein.

Claims

1. A solid state proximity collimation stack comprising: a. a substrate layer; b. one or more electromagnetic emitters (200) in fixed positions on the substrate layer; c. a first electromagnetic radiation reflecting and selecting layer (102) covering the one or more emitters (200), the first electromagnetic radiation reflecting and selecting layer comprising a material including one or more electromagnetic transparent pinholes (113) aligned with each emitter to form emitter-pinhole pairings; d. a spacer layer (103) covering the first selecting layer, the spacer layer comprising an optically absorbing or black body material and containing for each emitter-pinhole pairing a channel in optical alignment therewith; e. a second electromagnetic radiation reflecting and selecting layer (104) configured to cover the spacer layer (103), the second electromagnetic radiation reflecting and selecting layer comprising a material containing for each channel in the spacer layer an electromagnetic transparent pinhole (110) in optical alignment therewith; and, f. a top layer (105).

2. The proximity collimation stack of claim 1, wherein each of the one or more electromagnetic emitters is operable to transmit electromagnetic radiation at one or more wavelengths in the infrared, visible, or ultraviolet spectrum.

3. The proximity collimation stack of claim 1, wherein the emitted light exiting the stack is confined to a narrow angular range via reflection and absorption of light outside the range.

4. The proximity collimation stack of claim 1, wherein the emitted light exiting the stack is approximately parallel to each other.

5. The proximity collimation stack of claim 1, further comprising: g. an absorbing layer (101) between the substrate layer and the first selecting layer (102) and containing for each present emitter an absorbing column, each column configured to enclose a corresponding emitter.

6. The proximity collimation stack of claim 1, wherein the pinhole diameters of the first and second electromagnetic reflecting and selecting layers are less than or equal to 2 millimeters and the thickness of the selecting layers is less than or equal to 500 microns.

7. A solid state system for optical measurement of a fluid sample comprising: a. a proximity collimation stack comprising: i. a substrate layer; ii. one or more electromagnetic emitters (200) in fixed positions on the substrate layer; iii. a first electromagnetic radiation reflecting and selecting layer (102) covering the one or more emitters (200), the first electromagnetic radiation reflecting and selecting layer comprising a material including one or more electromagnetic transparent pinholes (113) aligned with each emitter to form emitter-pinhole pairings; iv. a spacer layer (103) covering the first selection layer, the spacer layer comprising an optically absorbing or black body material and containing for each emitter-pinhole pair a channel in optical alignment therewith; v. a second electromagnetic radiation reflecting and selection layer (104) configured to cover the spacer layer (103), the second electromagnetic radiation reflecting and selection layer comprising a material containing for each channel in the spacer layer an electromagnetically transparent pinhole (110) in optical alignment therewith; and, vi. a top layer (105); b. a sample holding component (505) configured to accept one or more fluid samples or a container comprising one or more fluid samples; c. an optical detection system (300) comprising one or more optical receivers (301); and, d. an emitter-detector coupling assembly (500) comprising a rigid frame or a series of interlocking or semi-permanent coupling parts; wherein: each receiver (301) is operable to detect the electromagnetic radiation from at least one of the emitters (200); the sample holding component (505) is placed or can be configured to place the one or more fluid samples in optical alignment with the radiation of at least one emitter such that the radiation will pass through the one or more samples; and, the coupling assembly (500) temporarily or permanently causes the near-collimated stack, the sample holding component (505), and the optical detection system to be durably aligned such that at least one of the emitted light of the emitters is in optical alignment with at least one sample and the emitted light of the emitters passes through the sample to at least one receiver.

8. The solid state system of claim 8, wherein the near-collimated stack further comprises: vii. an absorbing layer (101) located between the base layer and the first selection layer (102) and containing for each present emitter an absorbing column, each column configured to enclose the corresponding emitter.

9. The solid state system of claim 8, wherein there are equal numbers of emitters, first selection layer pinholes, spacer layers, second selection layer pinholes, and optical receivers.

10. The solid state system of claim 8, wherein the pinhole diameters of the first and second electromagnetic reflecting and selection layers are less than or equal to 2 millimeters and the thickness of the selection layers is less than or equal to 500 micrometers.

11. The solid state system of claim 8, wherein the coupling assembly (500) comprises a single rigid housing configured to block interfering electromagnetic emitted light from outside the frame or coupling parts but containing an opening for insertion of one or more samples.

12. The solid state system of claim 8, wherein the coupling assembly comprises two rigid housings configured to couple and decouple from one another such that the one or more emitters and the one or more optical receivers are optically aligned when the housings are coupled.

13. The solid state system of claim 13, wherein one housing contains the proximity collimation stack and one housing contains the optical detection system and when they are coupled define the sample holding component (505).

14. A method for making optical measurements of a fluid sample by passing collimated electromagnetic (EM) radiation through an aperture containing the fluid sample, the method comprising: a. Beam shaping EM radiation using a proximity collimation stack; b. Directing the beam shaped radiation through the fluid sample contained in the aperture.

15. The method of claim 14, further comprising: c. Detecting the radiation after passing through the sample via an optical receiver.

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