Abstract
Determination of the surface anchoring strength at a liquid crystal-substrate interface is a highly delicate measurement which could be easily corrupted by a number of experimental and conceptual ambiguities. Although the high-electric-field technique has been established as a reliable method for polar anchoring measurement, it still suffers from a few shortcomings associated with the use of electric field and optical retardation; as a result, it remains difficult to apply the method to the extremely high anchoring strength and to the azimuthal anchoring measurement. We show in this paper that the use of mechanical torque measurement in conjunction with a strong magnetic field removes all these problems. thereby making the high-field technique universally applicable to both polar and azimuthal anchoring without loss of precision even for the strong anchoring cases.
