• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.86-91
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• 2007

A sensor using quartz toning fork is presented for measuring liquid density. It consists of a PZT plate as an actuator for piezoelectric excitation and a quartz tuning fork as a sensor for resonant frequency detection. The resonant frequency is determined from the sensing voltage measured in tuning fork when the excitation frequencies of PZT actuator are swept around the resonant frequencies of tuning fork. The resonant frequency determined the liquid density. The density values of three kinds of organic solvents are measured and compared with the standard values. The experimental results are in agreement with the standard values and the maximum standard deviation is less than 9%.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.35-40
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• 2005

An experimental Investigation of the basic characteristics of a micro-cantilever sensor was performed by inspecting the amplitude and frequency characteristics of a commercial tuning fork (TF). Application of acetone and ethanol with a volume of $1{\mu}l$ on the tine of a vibrating tuning fork causes immediate response in its amplitude and frequency characteristics. It has been shown that the tuning fork has ability to recognize a chemical agent with high sensitivity. The theoretical sensitivity of mass loading is in the range of $\~0.1Hz/ng$. Quartz tuning forks are routinely made using standard microfabrication process, thus suggesting the possibility of microfabrication of micro quart sensors.

• Korean Journal of Optics and Photonics
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• v.14 no.1
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• pp.80-84
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• 2003

We have constructed a scanning confocal microscope by directly oscillating an optical fiber in two different ways. Either a piezoelectric transducer or a tuning fork was used for the oscillation. Six frames of $640{\times}480$ pixel image were obtained in a second with piezoelectric oscillation and only one image of the same size was obtained in a second with tuning fork oscillation. Oscillation of optical fiber did not cause amy distortion of confocal images.

• Vacuum Magazine
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• v.3 no.4
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• pp.14-18
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• 2016

In this article, we will summarize recent advances in ultrahigh vacuum (UHV) low-temperature scanning tunneling microscopy (STM) during the last decade. Leading STM groups have finished or are constructing UHV milli-Kelvin high magnetic field STM capable of a few tens of milli-Kelvin and ~ 10 tesla. Applications with UHV sub-Kelvin high magnetic STM have been increased since mid-2000's. Active research using UHV low temperature tuning fork atomic force microscopes and UHV photon low-temperature scanning tunneling microscopes will be introduced. Considering these advances of UHV low-temperature STM we will discuss next trend in STM in the near future.