Fluid immersion control for inverted microscopy

A microscope objective for fluid immersion for inverted microscopy, the microscope objective comprising:

• a sensor ring coupled to a distal portion of a microscope objective used with an inverted microscope, wherein the sensor ring forms an annulus in fluid communication with the microscope objective, wherein the annulus is enabled to convey a fluid that forms an immersion layer at a surface of the microscope objective during imaging using the microscope objective, and wherein the sensor ring further comprises:
• a plurality of sensor electrodes located circumferentially about the annulus, wherein each of the sensor electrodes remains in contact with the immersion layer when the fluid immerses the microscope objective;
• a common electrode located within the annulus, wherein the common electrode remains in fluid communication with the fluid;
• and
• a fluid port to receive additional fluid to replenish the immersion layer;
• wherein the microscope objective is enabled to operate with:
• a fluid replenishment system coupled to the fluid port and enabled to provide the additional fluid;
• an immersion controller coupled to the sensor electrodes, the common electrode, and the fluid replenishment system, the immersion controller enabled for:
• when the fluid immerses the microscope objective, measuring a first resistance of the fluid, respectively, between each of the sensor electrodes and the common electrode, to detect the fluid at each of the respective sensor electrodes;
• when the fluid exposes a first sensor electrode included in the plurality of sensor electrodes, measuring a second resistance of an air gap at the first sensor electrode;
• and
• responsive to detecting the air gap, controlling the fluid replenishment system to provide the additional fluid.

A method for inverted immersion microscopy, the method comprising:

• using a microscope objective to view a first sample included in a plurality of samples loaded into an inverted microscope, wherein the microscope objective is immersed in a fluid at a distal portion of the microscope objective, wherein the microscope objective further comprises:
• a sensor ring coupled to the distal portion and forming an annulus in fluid communication with the microscope objective, wherein the annulus is enabled to convey the fluid, and wherein the sensor ring further comprises:
• a plurality of sensor electrodes located circumferentially about the annulus, wherein each of the sensor electrodes remains in contact with the fluid when the fluid immerses the microscope objective;
• a common electrode located within the annulus, wherein the common electrode remains in fluid communication with the fluid;
• and
• a fluid port to receive additional fluid from a fluid replenishment system to replenish the fluid;
• and
• using an immersion controller coupled to the sensor electrodes, the common electrode, and the fluid replenishment system, maintaining the fluid over an optical axis diameter of the distal portion when at least one of the microscope objective and the first sample are moved with respect to each other.