Fabrication of Microscope Stage for Vertical Observation with Temperature Control Function

This device can be used to fix a sample to a vertical microscope stage to allow observation of the influence of gravity and working on the sample of interest. Attachment of this device to the stage allows the observation of sample dynamics in the vertical frame and permits the observation of temperature-dependent sample behaviors. To fabricate the aluminum plates, use a laser processing machine to cut a 101-millimeter hole in the center of a 150 by 200 by two-millimeter aluminum plate to be used as the forefront plate.

Make claws at eight points around the outside of the plate to allow two rubber bands to affixed across the length or the width of the plate. Next cut a 130-millimeter hole in the center of a 150 by 200 by five-millimeter aluminum plate to be used as the middle-upper plate, and make eight notches to allow the placement of two rubber bands across the length or width of the plate. Then cut a 130-millimeter hole in the center of a 150 by 200 by four-millimeter aluminum plate to be used as the middle-lower plate, and cut a 30-millimeter hole in the center of a 150 by 200 by 1.5-millimeter aluminum plate to be used as the base plate.

To fabricate the pedestals, cut a 30-millimeter hole in the center of a 100-millimeter-diameter, three-millimeter-thick aluminum plate, and make a 42-millimeter-wide by 30-millimeter-deep notch on one side of the plate. Then cut a 30-millimeter hole in the center of a 100-millimeter-diameter, four-millimeter-thick aluminum plate, and drill three three-millimeter holes 25 millimeters from the center of the plate and spaced 120 degrees from each other. For fabrication of the pressed cork disks, use a water jet cutting machine to cut a 20-millimeter hole in the center of a 100-millimeter-diameter, two-millimeter-thick pressed cork disk, and make one 42-millimeter-wide by 30-millimeter-deep and one four-millimeter-wide by five-millimeter-deep notch on each side of the disk.

Next cut a 20-millimeter hole in the center of a 100-millimeter-diameter, one-millimeter-thick pressed cork disk, and make one 42-millimeter-wide by 30-millimeter-deep and one four-millimeter-wide by 40-millimeter-deep notch on each side of the disk. Then cut a 42-millimeter-wide by 30-millimeter-deep pressed cork plate from a 100-millimeter-diameter disk. To fabricate a silicone rubber heater, cut a 20-millimeter hole in the center of a 100-millimeter-diameter, 2.5-millimeter-thick silicone rubber disk with a built-in nichrome wire.

Then stack the fabricated parts as demonstrated, fixing the appropriate pieces with screws or adhesive as required. Use a dedicated cable to incorporate the rubber heater and the heater of the controller case to connect the microscope stage to the system, and use the controller to equip a Wi-Fi signal and control the current of the rubber heater. After building the system, connect the thermistor wire to the sensor terminal on the controller case, and receive the temperature signal measured by the thermistor.

Use the knob on the controller to change the set temperature. Then transfer the measured temperature, set temperature, and time information at measurement from the controller to the server via the internet. To analyze the sample, place the sample on the microscope stage perpendicular to the ground surface, and use the four lengthwise claws to secure the sample with two rubber bands.

Use the controller to set the temperature to 40 degrees Celsius, and check the temperature on the display. Then press the knob to start temperature control. The blue LED will light up, indicating the initiation of the heat supply.

In these figures, representative temperature distributions of the rubber heater are shown. The surface temperature of the rubber heater was uniform at each temperature. Here, an example of the responsiveness of the measured temperature to set the temperature changes is shown.

The orange line indicates the set temperature, and the blue line shows the change of the sample temperature. If the equipment is assembled correctly, the overshoot of the measured value to the setting change is typically small, and the tracking is quick. In this experiment, the temperature-dependent vertical motion of diatoms was successfully recorded, allowing the locus of the vertical motion of the diatoms to be detected.

The effects of thermal convection on the vertical floating phenomenon of the diatom cells could then be visualized by direct observation. When the sensor is disconnected from the sample, or if the microcontroller does not operate properly, check whether the current to the heater has been cut off from the microcontroller. Using this method, the effect of temperature changes on the vertical movement of an organism in water can be observed.

As the structure of the part of the stage that attaches to the microscope is complicated, future studies will address simplification of that structure. To cool samples to lower than room temperature requires a complicated cooling device which is also under consideration for future work.