Current state of the art in small mass and force metrology within the International System of Units

Abstract

This review article summarizes new scientific trends in research for metrology of small mass (1 mg and lower) and small force (10 micronewtons and lower). After a brief introduction to the field, this paper provides an overview of recent developments in methods that demonstrate traceability to the International System of Units (SI) with emphasis on the implications of redefining the kilogram in terms of Planck’s constant. Specific research applications include new metrology facilities, calibration of small mass and force references such as milligram to submilligram masses or atomic force microscope (AFM) cantilevers, and laser power measurement using radiation pressure forces. Also discussed are recent scientific developments that may impact the field moving forward in the study of ultrasmall forces present in trapped and cooled quantum mechanical systems, resonant micro- and nanomechanical mass sensors, and other areas that are potentially well suited for SI metrology. The work reviewed is not intended as a comprehensive review of all research in which small forces are measured, but rather as an overview of a field in which the accurate measurement of small mass and force with quantified uncertainty is the primary goal.

Sampling and Mass Detection of a Countable Number of Microparticles Using on-Cantilever Imprinting

“…Resonant-based mass sensing, like conventional macroscale mass measurements [42], is influenced by the loading position and environmental conditions such as relative humidity (RH) and temperature (T). A temperature change (ΔT) correspondingly changes f0 by multiplying it with ∆ [35], where α = 2.6 ppm/K and αE = −44 ppm/K [35,43] denote the linear coefficient of thermal expansion and temperature coefficient of Young's modulus E of silicon, respectively; while the change in relative humidity (ΔRH) is bound to decrease f0 due to the moisture that cling to the sensor surface.…”

“…Resonant-based mass sensing, like conventional macroscale mass measurements [42], is influenced by the loading position and environmental conditions such as relative humidity (RH) and temperature (T). A temperature change (∆T) correspondingly changes f 0 by multiplying it with…”

From μ 0 to e: A Survey of Major Impacts for Electrical Measurements in Recent SI Revision

“…Masses at the milligram level or below are calibrated by electrostatic balances [76]. A typical electrostatic balance uses a charged capacitor system to produce an electrostatic force that can be precisely measured, i.e.…”

Understanding the Revised SI: Background, Consequences, and Perspectives

“…Considerable research is underway at metrology institutes worldwide to develop portable table‐top Kibble balances . They address different mass ranges and accuracy classes such as for industrial applications or for verifying weights as recommended by the International Organization of Legal Metrology (OIML).…”