Disclosed herein are methods and systems for use in preparing a sample. The methods and systems may be used for lysing one or more structures in a sample (e.g., cells, viral particles, etc.). The methods and compositions may comprise a microfluidic chip or use thereof. The microfluidic chips disclosed herein may comprise (a) a substrate comprising a chamber, wherein at least one mechanical element may be located within the chamber; (b) a thermal element in contact with the chamber; and (c) at least one aperture within the surface of the substrate, wherein the aperture may be configured to insulate the chamber.