Cryo-preparation systems and methods for near-instantaneous vitrification of biological samples

A system for imaging a biological sample using a set of sample imaging wavelength ranges while preparing or fixing the biological sample, the system comprising:

• a sample capsule structure comprising:
• a thermal energy transfer substrate including a top face and a bottom face;
• a cover disposed opposite to the top face of the thermal energy transfer substrate, the cover comprising a material transparent or transmissive to the set of sample imaging wavelength ranges;
• a compartment disposed between the top face of the thermal energy transfer substrate and the cover, the compartment providing an internal volume in which the sample can be carried, and in which the sample is exposable to or carried by a fluid;
• and
• a set of microfluidic elements configured for introducing the fluid into and withdrawing the fluid out of the internal volume of the compartment;
• an electromagnetic signal source configured to generate microwave frequency signals in accordance with microwave signal parameters that are timed or synchronized relative to ice crystal growth dynamics;
• a microwave applicator coupled to the electromagnetic signal source and comprising a set of microwave signal delivery elements configured for exposing the sample within the compartment to microwave radiation generated in accordance with the microwave signal parameters while the sample is exposed to the fluid, wherein the microwave radiation has an average power density that avoids sample heating and an instantaneous power density that disrupts ice crystal nucleation events, and wherein the microwave radiation arrests initial ice crystal nucleation events in the sample within tens of microseconds;
• and
• a cryogenic cooling unit configured for selectively directing a cryogenic coolant jet to the bottom face of the thermal energy transfer substrate while the microwave applicator exposes the sample within the compartment to the microwave radiation during cryogenic cooling of the sample,
• wherein the thermal energy transfer substrate has a very high or extremely high thermal conductivity that enables cryogenic cooling of the substrate at a rate greater than approximately 5,000 degrees/sec.