A force sensor for atomic point contacts

Abstract

We have developed a sensor to study the mechanical stiffness of atomic-size contacts. It consists of a modification of the mechanically controllable break-junction technique, using a quartz tuning fork resonator as force sensor. We present first results of measurements of the force constants in gold atomic contacts. In the formation of chains of single-metal atoms, the folding in of individual atoms from the banks into the chain can be observed. This sensor allows one to measure forces in atomic contacts for a wide variety of metals, as illustrated with the first measurements on platinum.

Investigation of QTF based gas sensors

“…These QTFs can be considered to be mechanical transducers, since changes in the mechanical properties of the system can be monitored by measuring the change in resonant frequency of the system, which is measured in the form of an electrical signal. In recent years, QTFs have been widely used as a sensor due to its high stability, precision, Q factor, low power consumption and high thermal stability [22,23]. Such sensors have been reported to have slow response time since it is governed by the diffusion rate of gas molecules [24].…”

Mechanical properties of Pt monatomic chains

“…10. Compared to the STM-AFM system, which has been used in most experiments on microscopic force measurement, the advantages of our system are as follows: ͑1͒ Our system increases mechanical stability, permitting a statistical analysis of measurements of many different monatomic chains.…”

Femto-Newton force sensitivity quartz tuning fork sensor

“…The use of quartz tuning fork resonators has become very popular in a variety of scientific instruments, especially in near field optical microscopes [1][2][3][4], atomic and magnetic force microscopes [5,6], high sensitivity magnetometers [7], atomic point contact sensors [8], and spectroscopic gas sensors [9]. The attractive features of this type of sensor are numerous.…”