LEMOLISH
The Project
LEMOLish is a motorized LEGO®-based light sheet microscope built to acquire scientific 3D images from centimeter-sized optically cleared biological samples. The system is open source, versatile, and costs about a hundred times less than existing custom/commercial solutions! This website summarizes the concepts of the project and provides access to the blueprint material (still under construction but fully available soon).
What's the catch?
LEMOLish relies on an innovative and compact optical design to create an array of thin light sheets without complex optical alignment. Combined with low noise affordable industrial CMOS cameras, the resulting image quality reaches scientific grade. No expensive medium-corrected objective lenses are required to acquire Z-stacks through the sample chamber thanks to the automated repositioning of the light sheet at the image plane. The images can be taken simultaneously from two detection sides (two cameras needed) and can be easily recombined so as to avoid typical deep-imaging image degradation. Altogether, the system achieves "stripe-free" 3D imaging at low cost and without tedious optical adjustments, expensive parts or complex image post-processing.
How does it work?
The control of the moving parts at micro-metric resolution is entirely performed by LEGO bricks and motorized LEGO MINDSTORM EV3 components. To trigger up to two lasers (dual channel imaging) and two cameras (dual side imaging), a simple electronic board with external power supply has been designed. The sample is sitting inside a fully independent quartz/ glass chamber and it can be rotated by a pair of communicating magnets. Inexpensive laser diodes and an innovative combination of glass capillaries and a single cylindrical lens enables to create a thin array of light sheets. A custom software is provided to drive the microscope (directly from the LEGO® EV3 brick) and to combine the image stacks taken from both detection sides (Matlab executable). It is also possible to fuse 180 (+/-30) degree views (achieved with sample rotation) so as to maintain the image quality throughout the sample in the orthogonal direction (illumination sides).See all these functional parts working together
Gallery
Links to an interactive browser page to view and interact with 3D stacks from LEMOLish
(warning: data is downloaded locally)
Chicken embryo HH36: Autofluorescence (downsampled 38MB stack)
Chicken embryo HH36: Bones (downsampled 38MB stack)
Seahorse (downsampled 31MB stack)
Mouse embryo E18.5 (Surface only: downsampled 27 MB model)
Components
LEGO building Instructions
LEMOLISH plans for the LEGO bricks architecture are available for download from the following links (LEGO parts exclusively, no optics in this file).
LXF FILE FOR LDD,
IO FILE FOR STUDIO,
The .lxf file was generated with LEGO Digital Designer v.3.11 and the .io file with Stud.io. Both configurations are the same, but the colors of the bricks vary. The full list of parts can be generated directly from both software pack. WARNING: Not all bricks are always available from the original LEGO store (find the "purchase replacement parts" section in the page for your country), but you can complement the order with missing pieces from secondary market places for LEGO bricks, e.g. Bricklink.
Electronics
PCB Gerber (recommended to print @ Eurocircuits)PCB
PDF mask (for home printing)
2x EV3 connectors (J1 & J2)
1x DC Power connector (J3)
6x 1K Ohm resistors (Rx)
1x 2V Zener diode (Z1), optional: to adapt 5V power supply to 3V laser if needed2x FQP30N06L MOSFET transistors (Q1 & Q2)
3x 2 poles PCB terminals (C1, C2 and C3)
Camera(s)
The cameras must have the option of an external trigger to take a snapshot!
We recommend "The Imaging Source" USB 3.0 cameras from the 33 series that provide a good trade-off between price and performance (we use the DMK23UX174 because of the large pixel size of 5.86um). To connect the external trigger to the custom board, this camera needs an Hirose 12 way female cable: connect and trigger + (pin 12) to Trigger Vcc and trigger - (pin 11) to Trigger ground of the corresponding 2 pole PCB terminal.
Lasers
The dimensions and optical power of the laser diodes are critical considerations. We recommend to buy cylindrical-case "OEM" or "dot" Lasers diodes with maximum length approx. 6cm, with two or three wires (power supply + trigger). We recommend 10 to 50 mW optical power to enable sufficient fluorescence excitation when using low-magnification lenses, and 3 to 5V power voltage. The wavelength should be chosen according to your application, and the optical filters accordingly. For three wires Lasers, simply connect trigger and Vcc to the same PCB terminal (Vcc). Make sure that the external DC power supply you buy is compatible with both Lasers voltage and with the DC power connector!
Optics and accessories
You only need a capillary, one cylindrical lens and one filter to get started.
You will need a cylindrical lens with sufficient "height" (dimension in the non-focusing axis) so as to direct the diverging beam into it without being truncated. We recommend this lens from Thorlabs. Optical filters need to be chosen according to your lasers. For a good and economical start, you can use colored glass Longpass filters: with a 450nm laser we used this one, with a 532nm laser we used this one. For a 635nm laser and far-red dyes, we preferred a higher performance filter given the lower sensitivity of the cameras in that range: this one. Always take into account that lasers' central wavelength and spectral bandwidth are variable (at manufacturing), hence the filters' transition (from blocking to transmitting) should not be adjusted to close to the nominal laser wavelength given by the provider. For diverging lightsheet formation, we recommend a water-filled and sealed capillary of diameter well above the laser beam diameter, e.g. 1 or 2mm diameter and max length between 7 and 10cm. For pixel calibration, we recommend to use a Ronchi Mask. The destriper can be created with stacked 1mm glass rods.
Software
The software to control the LEMOLISH and combine image stacks acquired during dual camera/view/channels experiments
Connect With Us (coming soon)
