absorber

Absorber refers to any material, device, or system that captures and retains energy, particles, or substances from its environment, converting them into another form or storing them for later use. In physics and engineering, absorbers are employed to manage electromagnetic, acoustic, thermal, or mechanical energy. Optical absorbers, such as black coatings or photovoltaic cells, convert incident light into heat or electrical energy. Acoustic absorbers, made from porous foams, fibrous panels, or resonant panels, dissipate sound waves by converting acoustic energy into heat, thereby reducing reverberation and noise levels. Thermal absorbers, including heat‑sink plates and phase‑change materials, absorb heat and release it gradually, aiding temperature regulation in electronic and building applications.

Chemical absorbers capture specific gases or vapors through physical adsorption or chemical reaction. Activated carbon, zeolites, and metal‑organic frameworks are common solid adsorbents used in air purification, water treatment, and industrial gas separation. Liquid absorbers, such as aqueous alkaline solutions, scrub acidic gases like sulfur dioxide in flue‑gas desulfurization processes. In radiation protection, absorbers composed of dense metals like lead or concrete attenuate ionizing radiation by absorbing photons and particles.

The performance of an absorber depends on material properties, surface area, thickness, and the spectral or frequency range of interest. Design considerations often involve trade‑offs between absorption efficiency, durability, cost, and environmental impact. Absorbers play a critical role in energy efficiency, environmental control, and safety across multiple sectors, including aerospace, architecture, manufacturing, and renewable‑energy technologies.