Hey there,

Yes, ultrasonic bubbles generation is a physical technique that can be used to create highly porous materials. The process involves using ultrasonic energy to generate and collapse bubbles in a liquid, which can then create voids in the paste, resulting in a highly porous material. It is a non-destructive process that can be easily scaled up for industrial applications.

The porosity of the paste can be controlled by adjusting the ultrasonic energy and liquid content of the paste. However, it's worth noting that there are some limitations with this method. For example, you need a liquid medium in the paste and it can be difficult to control the size and distribution of the pores. Additionally, the porosity that can be obtained with this method is typically lower than that obtained with chemical methods such as the use of expanding agents.

It's recommended to conduct experimental studies to determine the optimal conditions for creating highly porous pastes using ultrasonic bubbles generation. But keep in mind that you can also consult with experts in the field to help you with this process.

Hope this helps!