μN/m
micronewton per meter
Surface tensionexact by definition
The micronewton per metre is 10⁻⁶ N/m, exact by prefix, or 10⁻³ mN/m. It is the scale of ultralow interfacial tension: surfactant flooding in enhanced oil recovery aims to drive the oil-water interfacial tension down into this range, because that is what lets trapped oil deform through pore throats.
| 1 μN/m | 0.001 mN/m |