Part List
The design files for the Miniscope housing and base plate can be found in the "3D-Printed-Bodies_MiniLFOV" folder of this repository. The files are saved as both Fusion 360 design files and as STL files. The bodies can be printed using the Formlabs Form3 printer and their black resin. These components have been designed to be modular, allowing researchers to swap them in and out depending on the features needed. Below is a description of these parts:
Protective cap is used for protecting the GRIN lens and surgical region when not recording.
The Rigid-Flex PCB holds all the on-board electronics needed for the MiniLFOV. It contains a U.FL coax connector, voltage regulators, serializer, CMOS imaging sensor, BNO055 head orientation sensor, excitation LED and driver, and electrowetting lens driver. If you need to do any soldering rework on this board, it should be baked at 120 degrees C for at least 2 hours before hand.
The KiCad, BOM, gerbers, and Pick and Place files are provided in this repository. More details can be found on the Rigid Flex PCB page.
The majority of the documentation for the MiniLFOV is centered around imaging neural activity using GCaMP. That being said, by swapping out the LED and filter set, the Miniscope is capable of imaging most fluorophores. Most filter manufacturers can dice any of their filters to custom sizes, just remember the standard MiniLFOV design was designed to work with 1mm thick filters. Thinner or thicker filters might require additional modification.
The excitation filter is a 4mm x 4mm x 1.1mm band-pass optical filter used to narrow the spectrum of the excitation LED. For exciting GCaMP's we suggest using:
- Vendor: Chroma
- Part Number: ET470/40x
- Note: Diced to 4mm x 4mm in size
The emission filter is a 10mm x 10mm x 1mm long-pass or band-pass optical filter used to block out any remaining excitation light from the imaging sensor. For imaging GCaMP's fluorescence we suggest using:
- Vendor: Chroma
- Part Number: ET525/50m
- Note: Diced to 10mm x 10mm in size
TThe dichroic is a 14mm x 10mm x 1mm filter used to reflect short, excitation wavelengths and pass longer, emission wavelengths. For imaging GCaMP's fluorescence we suggest using:
- Vendor: Chroma
- Part Number: ET500spxr
- Note: Diced to 14mm x 10mm in size
Three achromatic lenses make up the majority of the optical imaging path. Three achromatic lenses L1 (d=6.25 mm, focal length=60 mm, #45-345, Edmund Optics), L2-1 (d=9 mm, focal length=12 mm, #49-656, Edmund Optics), and L3-1 (d=9 mm, focal length=27 mm, #45-092, Edmund Optics) are used to build the 1.8-mm-WD objective module with a 3.5 mm tall spacer placed between L2-1 and L3-1. One aspherical lens (d=12.5 mm, focal length=14 mm, #49-658, Edmund Optics) and a concave lens (d=12 mm, focal length=-48 mm, #45-019, Edmund Optics) with a lens holder are placed into the emission module body to form the tube lens of the MiniLFOV. For more information on that visit the Lens Configurations page. Below outlines the standard configuration which achieves single cell resolution, ~3.1mm X 2.3mm diameter FOV, and 1.9mm working distance:
Three achromatic lenses make up the majority of the optical imaging path. Two of these lenses are 3mm diameter lenses and sit in the Objective Module, the third is a 4mm lens in the Emission Module and acts as a focusing tube lens. By mix and matching the focal lengths of the two lenses in the Objective Module, a range of working distances and fields-of-view can be achieved. For more information on that visit the Lens Configurations page. Below outlines the standard configuration which achieves single cell resolution, ~1mm diameter FOV, and ~1mm working distance:
| Lens Number | Vendor | Part Number | Description |
|---|---|---|---|
| 1 | Edmund Optics | 45-345 | 6.25mm diameter, 60mm FL achromat used in the objective module |
| 1 | Edmund Optics | 49-656 | 9mm diameter, 12mm FL aspherized achromat used in the objective module |
| 1 | Edmund Optics | 45-092 | 9mm diameter, 27mm FL achromat used in the objective module |
| 1 | Edmund Optics | 49-658 | 12.5mm diameter, 14mm FL aspherized achromat used in the emissioin module |
| 1 | Edmund Optics | 45-019 | 12.0mm diameter, -48mm MgF2 Coated, Plano-Concave Lens used in the emission module |
The electrowetting lens (EWL) provides electronic focal length adjustment controllable through the Miniscope DAQ Software. The range of focal length adjustment depends on the other optics used in the optical path. When using the standard MiniLFOV optical configuration, this EWL provides +/-150um of adjustment. The EWL can be purchased from multiple vendors.
- Manufacturer: Corning (Varioptics)
- Part Number: Corning Arctic 58N
- Description: The A-58N lens is designed specifically for variable focus products needing a large clear aperture and high optical quality; such as optical instruments for life sciences, ophthalmology, scientific instruments, and microscopes. The new large aperture lens features 15 diopters of dynamic range, 7 cm focus ability, and offers the same low power consumption, high shock resistance, and fast-focus ability
| Lens Number | Vendor | Part Number | Description |
|---|---|---|---|
| 1 | Varioptics/Corning | Corning Arctic 58N | Corning® Varioptic® Lenses introduces new A-58N variable focus liquid lens |
Just like previous Miniscopes, the MiniLFOV uses a 50Ohm coaxial cable for power, communication, and data. Any 50Ohm coax cable should work with the system but, in general, the thinner the cable, the shorter it must be. For a rough guideline: a 0.3mm diameter coax cable like cannot be longer than 5 ft, a 1mm diameter coax cable can likely function at lengths over 15 feet.
Our go-to coax cable for freely behaving experiments (with a good trade off between weight, size, flexibility, and robustness) is:
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Vendor: Cooner Wire (can be purchased at other places too)
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Part Number: CW8251
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Description: Coax cable. 36AWG 26/50SPC TRANSCUCENT PFA TO .016" NOM. O.D. 44AWG SPC SHIELD WITH .010" WHITE SILICONE RUBBER JACKET TO .045" NOM O.D. For thinner cabling, mouser sells a 0.3mm diameter Molex coax cable that works well:
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Vendor: Mouser (others)
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Mouser Part Number: 538-50MCX-37
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Part Number: 100065-0023
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Description: Coaxial Cables 42AWG PFA, 50 OHM MICRO COAX, PER FT
- Manufacturer: Hirose
- Vendor: Digikey, Mouser
- Part Number: U.FL-PR-SMT2.5-1(10)
- Description: RF Connectors / Coaxial Connectors U.FL SMT PLUG F CONTACT 50OHM
- Important Note: These connectors are not designed to be repeatedly connected and disconnected. We suggest you keep connecting/disconnecting to a minimum and treat the connector/cable as part of the MiniLFOV, only swapping it out if the cable gets damaged. Hirose sells other U.FL connectors that will also work, some that come already connected to a coax cable (flexibility of cable may not be great though).
One end of the coax cable will connect to the V4 Minsicopes, the other end needs to have an SMA connector so it can connect to the Minsicope DAQ Box. There are many ways of connectorizing a coax cable with an SMA connector but since you will likely be using thin, less standard coax cables, we have designed a simple PCB to help facilitate this connectoriztion. You can find the PCB here:
You will also need a side mount SMA connector:
Vendor: Digikey Part Number: CONSMA013.062-ND
| Quantity | Vendor | Part Number | Description |
|---|---|---|---|
| 12 | McMaster-Carr | 96817a704 | M1 thread-forming screws |
| 8 | McMaster-Carr | 92196A052 | 18-8 Stainless Steel Socket Head Screw, 0-80 Thread Size |
| 2 | Thorlabs | SS4S025 | 4-40 Stainless Steel Setscrew, 1/4" Long |
T2 Torx Screw Driver for M1 thread-forming screws:
- Vendor: McMaster
- Part Number: 52995A24 Filter paper or Kim Wipes