Crown jewel · interactive apparatus

Casimir force control,
made inspectable.

Engineered 3D nanostructures reshape the Casimir force — up to 10× on a single pillar (Shelden et al., Nano Letters 2025). Choose a geometry, drag the separation, and watch the force-gradient spectrum and live readouts move against the sphere-plate baseline. Educational model; not to scale.

CASIMIR FORCE CONTROL · 3D NANOSTRUCTURE APPARATUS
Shelden et al., Nano Lett. 2025, 25, 9254–9261 · gold sphere rs=33.1 µm · k=0.3 N/m · PFA + Lifshitz/Drude · DOI ↗
SEPARATION d80.0 nm
FORCE GRADIENT δF— mN/m
vs PLATE×0.24
PLATE CONTRIB.15 %
APPARATUS · SIDE VIEW (not to scale)● OSCILLATING
FORCE-GRADIENT SPECTRUM · δF vs d
GEOMETRY
PILLAR RADIUS rp600 nm
300 · 600 · 1200 · 3000 nm fabricated · hp=120 nm
SET SEPARATION d80.0 nm
30 nm ←——→ 3000 nm (log)
RESEARCH STATUS · what this apparatus does and current stage
ESTABLISHEDGeometry modifies Casimir force behavior — measured for pillars, hollow cylinders, and arrays (Shelden 2025; Wang 2021; Intravaia 2013).
MODELINGThis educational model shows how geometry changes the force-gradient trend. Publication-grade modeling requires full material response, roughness, thermal behavior, patch potentials, and geometry treatment.
CURRENT STAGEEducational model and research-stage measurement path.
NEXT TESTReproduce published geometry-force curves computationally, then measure through an AFM/KPFM partner.
EQUATION
FPFA(d) = ∫S Pplate–plate(H(x)) dA
ASSUMES
Sphere radius R ≫ gap d; locally flat surface; gold via a Lifshitz/Drude permittivity.
LIMITATIONS
Publication-grade results need full Lifshitz pressure, real-material permittivity, roughness, and patch-potential correction.