Surface tension control technique: The mini microplate centrifuge uses a vertically fixed rotor and instantaneous centrifugation design to accurately utilize liquid surface tension and avoid liquid leakage from the 96 well plate
The core of preventing liquid leakage from 96 well plates in mini microplate centrifuges lies in precise control of liquid surface tension. Its design ensures stable adhesion of the liquid to the bottom of the orifice plate during high-speed centrifugation through dual optimization of physical structure and operational logic.
Vertical fixed rotor design is the key foundation. The 96 hole plate is vertically inserted into the rotor through the top slot, so that the hole plate is parallel to the centrifugal axis. Under this layout, the liquid is pressed towards the bottom of the orifice plate by centrifugal force, while the surface tension forms a reverse tension, and the two reach dynamic equilibrium in the vertical direction. Experimental data shows that when the rotational speed stabilizes at 2500 revolutions per minute, the surface tension of the liquid can resist centrifugal forces exceeding 500g, ensuring that droplets will not be thrown out of the hole wall due to inertia.
Instantaneous centrifugation mode further enhances stability. After the user presses the button, the rotor accelerates to 2500 revolutions per minute within 0.5 seconds and then immediately stops. This short-term high-speed operation has two advantages: firstly, rapid acceleration instantly forms a stable liquid film, reducing droplet shaking caused by slow acceleration; Secondly, instantaneous stopping prevents the liquid from generating vortices due to continuous centrifugation, and prevents the surface tension from being disrupted. For example, in PCR experiments, instantaneous centrifugation can ensure sufficient mixing of primers and templates while avoiding uneven concentration caused by droplet wall attachment.
The synergistic effect of materials and processes. The rotor surface is coated with hydrophobic material to reduce the adhesion between liquid and metal, making surface tension the main guiding force. At the same time, the bottom of the orifice plate is designed as a micro arc shape to increase the contact angle between the liquid and the orifice plate, further enhancing the anchoring effect of surface tension. These details together ensure that even when handling high viscosity samples such as glycerol, the liquid can still adhere tightly to the bottom of the hole and will not leak due to centrifugal force exceeding the surface tension threshold.