Purdue University — Ruan Group

Snapshot

Country	United States
City	West Lafayette, IN
Tier	Engineered
Primary ecosystem	Engineered Emissivity
Unit	Ruan Group, School of Mechanical Engineering
Publicly linked people	Xiulin Ruan

Why it matters internationally

The Ruan group’s barium-sulfate radiative-cooling paints — 98.1% solar reflectance with strong sky-window emission — are the most visible demonstration that engineered emissivity scales from metasurfaces to paint cans, with peer-reviewed field tests behind the headlines.

Scope of activity

Quantities: solar reflectance · sky-window emissivity (engineered paints)
Spectral range: solar spectrum + 8–13 µm sky window
Temperature: field demonstrations under full sun
Methodology: BaSO4-based radiative cooling paints with 98.1% solar reflectance and high sky-window emissivity (the ‘whitest paint’); full-scale field cooling tests.

Application domains: radiative cooling paints · building energy.

External sources

Traceability

Every claim in this profile traces to the external sources listed above. Profile follows the research-map methodology. Added to the directory: 2026-06-11 (verified against the institution’s public pages or peer-reviewed publications).