Domain: Engineering — Biomedical Engineering
Target concept: The silicone membrane exhibits elastic deformation and fully recovers, while the polylactic acid membrane undergoes plastic deformation and does not fully recover.

Video generation prompt: Two transparent petri dishes are placed side by side on the desktop. The left dish contains a medical silicone membrane, while the right dish contains a medical polylactic acid membrane. Two identical rigid probes, each exerting the same downward force, descend and press both membranes at the same moment.

Evaluation guide:
(i) Target concept: Material-specific mechanical response (elastic vs. plastic deformation) under identical loading/unloading.
Minimum mechanism: Membranes must be isotropic, homogeneous, and initially flat; each probe must apply compressive normal force without shear or torsion; recovery must depend solely on intrinsic viscoelastic/plastic properties: no external constraints or adhesion effects.
(ii)Storyline: [Frame 0–2] Static setup: two transparent dishes side-by-side on desktop, each containing one membrane; left labeled/situated as silicone, right as polylactic acid. [Frame 3–5] Two probes descend and contact both membranes at the same moment: visible indentation begins in both. [Frame 6–7] Both probes fully withdrawn. [Frame 8–10] Left membrane surface returns completely to flat state; right membrane surface retains a static, non-recovering indentation. All events occur from fixed frontal viewpoint with no occlusion, ensuring unambiguous left/right discrimination and direct visibility of membrane surfaces.

Manual:
Experimental Procedure
1. Place two identical transparent petri dishes side-by-side on a flat desktop.
2. Place a medical silicone membrane in the left dish and a medical polylactic acid membrane in the right dish.
3. Simultaneously press both membranes with two identical rigid probes, each applying equal downward force.
4. Withdraw both probes completely.
Observation of Experimental Phenomena
After probe withdrawal: left membrane fully regains original flat shape; right membrane retains visible permanent indentation.
Summary of Experimental Principles
Silicone exhibits elastic deformation and full recovery; polylactic acid exhibits plastic deformation and incomplete recovery.

Prompt Grounding rubric:
level_1: No two petri dishes are present; or the dishes are not transparent; or a membrane is missing from either dish; or no probe is visible; or the camera angle makes it impossible to tell which dish is on the left and which is on the right.
level_2: Two transparent petri dishes sit side by side on the desktop, each holding one membrane, but at least one of: (a) the silicone membrane is not in the left dish or the polylactic acid membrane is not in the right dish, (b) only one probe is visible instead of two, (c) the two probes contact their membranes at clearly different times rather than together, (d) one membrane is never touched by a probe, (e) the dishes do not visibly rest on a desktop surface.
level_3: Two transparent petri dishes are side by side on the desktop, left holding the silicone membrane and right holding the polylactic acid membrane; two probes are visible and each contacts its own membrane; both probes begin contact within the same brief interval; the desktop, both dishes, both membranes, and both probes stay unobstructed and identifiable from a fixed frontal camera angle.
level_4: Everything at level 3 is shown, and in addition the two probes are visually matched in size and shape, each membrane sits centered in its dish so its full surface is visible during contact, and no unrelated object or hand blocks the view of either contact point for the full clip.
level_5: Everything at level 4 is shown, and in addition both probes press to a visibly similar depth at the moment of maximum contact, both membranes occupy a comparable surface area within their dishes, and no glare or reflection on either transparent dish obscures the membrane surface at any point in the clip.

Scientific and Causal Correctness rubric:
level_1: Neither membrane visibly deforms under probe contact; or both membranes deform identically and either both recover or both stay indented after the probes withdraw; or the polylactic acid (right) membrane recovers to flat while the silicone (left) membrane does not.
level_2: Both membranes visibly indent under probe contact, but the outcome does not distinguish elastic from plastic behavior: e.g., both fully flatten after withdrawal, both keep a permanent dent, the right membrane starts flattening again before both probes have withdrawn, or a membrane bulges outward instead of indenting where the probe pushes.
level_3: While the probes are in contact, both the silicone (left) and polylactic acid (right) membranes indent under the pressure; after both probes withdraw, the left silicone membrane returns to its original flat surface, while the right polylactic acid membrane keeps a visible dent where the probe pressed, and this contrast is clear to the eye.
level_4: Everything at level 3 holds, and in addition the indentation depth looks similar for both membranes while the probes are pressing, the left membrane's flat recovery is complete by the end of the clip, and the right membrane's dent shows no sign of self-flattening before the clip ends.
level_5: Everything at level 4 holds, and in addition the left membrane's recovery only begins once its probe has actually lifted away (not while still pressing), the right membrane's dent remains visible and unchanged for the rest of the clip after both probes are gone, and the right membrane is never seen looking flatter than the left at any point after both probes are withdrawn.

Spatiotemporal Consistency rubric:
level_1: One or both petri dishes change position or disappear between consecutive frames without the camera moving; a probe appears or vanishes mid-motion instead of moving continuously; a membrane's edge flickers or breaks apart; the desktop surface visibly warps or changes texture mid-sequence; the lighting on the scene swings abruptly between bright and dark with no visible cause; or the camera viewpoint itself cuts, pans, or zooms during the shot.
level_2: The camera stays fixed and no object vanishes, but at least one of: a probe's downward motion skips positions rather than moving smoothly; a membrane surface stretches or balloons beyond what a thin membrane could physically do; a dish rim blurs or dissolves partway through the clip; or a probe appears to pass through a dish wall instead of stopping at its surface.
level_3: Both petri dishes stay in the same place on the desktop for the whole clip; both probes descend and withdraw with smooth, continuous motion; each membrane's indentation and recovery (or lack of recovery) unfolds as a gradual surface movement rather than a sudden jump; no dish, membrane, or probe flickers, fragments, or splits apart.
level_4: Everything at level 3 holds, and in addition both probes keep a consistent size and angle as they move toward and away from the dishes, the highlight/reflection on the transparent dishes does not jump or swap sides between frames, and the desktop surface's texture looks the same in the first and last frame of the clip.
level_5: Everything at level 4 holds, and in addition the relative motion between the probes and the desktop looks physically consistent with a single fixed camera, no frame is blurred enough to hide either membrane's surface at the moment of maximum indentation, and viewing through each transparent dish wall does not distort or double the membrane's appearance.