Ohutkalvo

Ohutkalvo is a Finnish term that translates to thin film or thin membrane in English. It denotes a layer with very small thickness that forms a boundary on or coats a substrate. In scientific and technical Finnish usage, the concept covers both biological membranes and engineered coatings and films used in electronics, optics, and materials science.

In biology, ohutkalvo describes cellular and subcellular membranes, such as the plasma membrane and organelle envelopes. These structures are typically only a few nanometres thick and act as barriers that regulate transport, signaling, and integrity. They are mainly composed of lipid bilayers with embedded proteins and carbohydrate groups.

In engineering and materials science, ohutkalvo refers to deposited or formed layers that are much thinner than bulk materials. Thicknesses range from about one nanometre to several micrometres, with many applications in optics, electronics, and protection. Common fabrication methods include physical vapour deposition (sputtering, evaporation), chemical vapour deposition, spin coating, and electrochemical or chemical deposition. Materials used span inorganic oxides, polymers, metals, and organic–inorganic hybrids.

Applications include thin-film solar cells, optical coatings to tailor reflectivity and transmission, protective or barrier coatings, sensors, and edible films for food packaging. Properties of an ohutkalvo—such as thickness uniformity, adhesion, permeability, and optical or electronic performance—depend on material choice and fabrication method. Characterization methods often involve ellipsometry, profilometry, transmission electron microscopy, or atomic force microscopy.

Because of their small thickness, ohutkalvot are sensitive to defects and stresses that can cause delamination or cracking. The term is common in Finnish scholarly and industrial contexts, while English-language sources typically use “thin film” or “membrane” depending on the context.