Figure 2.

Strategies for producing multiple pressure values in a single device using a cup and pumping lid. (A-D) Positive pressures produced by turning a pumping lid (grey) using a cup (blue) fit with a guiding structure (black) (A). Turning the lid within the guiding structure yields three potential lid positions, which are shown in side (B) and top (C) views, each of which produces a different pressure. In Position (i) the lid is not in contact with the cup, so no pressure is produced. In Position (ii) the lid is lowered and positive pressure is produced. In Position (iii) the lid is lowered further, and the pressure increases. The horizontal dashed lines show the level of the lid in the three positions. Panel D shows an experimental pressure profile obtained by turning the lid between the three positions. (E-H) Negative pressures produced by turning a pumping lid (grey), using an cup (blue) fit with a guiding structure (black) (E). Turning the guiding structure yields three potential lid positions, which are shown in side (F) and top (G) views, each of which produce a different pressure. The pumping lid and the cup have via-holes that align only in Position (i), so there is no gauge pressure in this configuration. In Position (ii) the lid is raised and negative pressure is produced. In Position (iii) the lid is raised further, and the pressure decreases. The horizontal dashed lines show the level of the lid in the three positions. Panel H shows an experimental pressure profile obtained by turning the lid between the three positions.