Surface-patterned SU-8 cantilever arrays for preliminary screening of cardiac toxicity

Kim, Jong Yun,Choi, Young-Soo,Lee, Bong-Kee,Lee, Dong-Weon Elsevier 2016 Biosensors & bioelectronics Vol.80 No.-

<P><B>Abstract</B></P> <P>Arrays of a μgrooved SU-8 cantilever were utilized to analyze changes in the contraction force and beating frequency of cardiomyocytes <I>in vitro</I>. The longitudinally patterned μgrooves facilitates alignment of cardiomyocytes on top of the SU-8 cantilever, which increases the contraction force of cardiomyocytes by a factor of about 2.5. The bending displacement of the SU-8 cantilever was precisely measured in nanoscale using a laser-based measurement system combined with a motorized <I>xyz</I> stage. The cantilever displacement due to contraction of the cardiomyocytes showed the maximum on day 8 after their cultivation. Following preliminary experiments, Isoproterenol, Verapamil, and Astemizole were used to investigate the effect of drug toxicity on the physiology of cardiomyocytes. The experimental results indicated that 1µM of Isoproterenol treatment increased contraction force and beating frequencies of cardiomyocytes by 30% and 200%, respectively, whereas 500nM of Verapamil treatment decreased contraction force and beating frequencies of cardiomyocytes by 56% and 42%, respectively. A concentration of less than 5nM of the hERG channel suppression drug Astemizole did not change the contraction forces in the displacement but slightly decreased the beating frequencies. However, irregular or abnormal heartbeats were observed at Astemizole concentrations of 5nM and higher. We experimentally conformed that the proposed SU-8 cantilever arrays combined with the laser-based measurement systems has the great potential for a high-throughput drug toxicity screening system in future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposes the utilization of micromachined SU-8 cantilever arrays to systematically characterize contraction force of cardiac cells. </LI> <LI> The µgroove patterns facilitates alignment of cardiomyocytes on top of the SU-8 cantilever, which increases their contraction force by a factor of around 2.5. </LI> <LI> The effect of various drugs on the contraction force of the cardiomyocytes is characterized using the SU-8 cantilever. The results reveal that the proposed technique can effectively realize the real-time screening of drug toxicity in cardiomyocytes. </LI> </UL> </P>

Performance of Different Sensors for Monitoring of the Vibration Generated during Thermosonic Non-destructive Testing

Kang, Bu-Byoung The Korean Society for Nondestructive Testing 2011 한국비파괴검사학회지 Vol.31 No.2

Vibration monitoring is required for reliable thermosonic testing to decide whether sufficient vibration is achieved in each test for the detection of cracks. From a practical point of view, a cheaper and convenient monitoring method is better for the application to real tests. Therefore, the performance of different sensors for vibration monitoring was investigated and compared in this study to find a convenient and acceptable measurement method for thermosonics. Velocity measured by a laser vibrometer and strain provide an equivalent HI when measured at the same position. The microphone can provide a cheaper vibration monitoring device than the laser and the heating index calculated by a microphone signal shows similar characteristics to that calculated from velocity measured by the laser vibrometer. The microphone frequency response shows that it underestimates high frequency components but it is applicable to practical tests because it gives a conservative value of HI.

Performance of Different Sensors for Monitoring of the Vibration Generated during Thermosonic Non-destructive Testing

강부병 한국비파괴검사학회 2011 한국비파괴검사학회지 Vol.31 No.2

Vibration monitoring is required for reliable thermosonic testing to decide whether sufficient vibration is achieved in each test for the detection of cracks. From a practical point of view, a cheaper and convenient monitoring method is better for the application to real tests. Therefore, the performance of different sensors for vibration monitoring was investigated and compared in this study to find a convenient and acceptable measurement method for thermosonics. Velocity measured by a laser vibrometer and strain provide an equivalent HI when measured at the same position. The microphone can provide a cheaper vibration monitoring device than the laser and the heating index calculated by a microphone signal shows similar characteristics to that calculated from velocity measured by the laser vibrometer. The microphone frequency response shows that it underestimates high frequency components but it is applicable to practical tests because it gives a conservative value of HI.

Performance of Different Sensors for Monitoring of the Vibration Generated during Thermosonic Non-destructive Testing

Bubyoung Kang 한국비파괴검사학회 2011 한국비파괴검사학회지 Vol.31 No.2

Vibration monitoring is required for reliable thermosonic testing to decide whether sufficient vibration is achieved in each test for the detection of cracks. From a practical point of view, a cheaper and convenient monitoring method is better for the application to real tests. Therefore, the performance of different sensors for vibration monitoring was investigated and compared in this study to find a convenient and acceptable measurement method for thermosonics. Velocity measured by a laser vibrometer and strain provide an equivalent HI when measured at the same position. The microphone can provide a cheaper vibration monitoring device than the laser and the heating index calculated by a microphone signal shows similar characteristics to that calculated from velocity measured by the laser vibrometer. The microphone frequency response shows that it underestimates high frequency components but it is applicable to practical tests because it gives a conservative value of HI.

레이저 진동 측정기를 이용한 초음파 이송 시스템의 동작특성에 관한 연구

정상화,신병수,이경형 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the vibration behavior of flexural beam in the ultrasonic transport system is verified using Laser Scanning Vibrometer. The experiments for verifying vibration are performed in three conditions such as in the maximum transport speed, in the zero speed, and in the change of transport direction.

초음파 여기를 이용한 물체 이송시스템의 메커니즘 연구

정상화,최석봉,차경래,김광호,박준호,이경형 한국공작기계학회 2004 한국공작기계학회 춘계학술대회논문집 Vol.2004 No.-

In the semiconductor and the optical industry a new transport system which can replace the conventional sliding system is required. These systems are driven by magnetic field and conveyer belt. The magnetic field damages semiconductor and contact force scratches the optical lens. The ultrasonic wave driven system can solve these problem. In this paper, the relationship of transporting speed according to the change of flexural beam shape and the effect of transporting speed according to the change of weight and amplification voltage are verified. The vibration behavior of flexural beam in the ultrasonic transport system is experimented using Laser Scanning Vibrometer.

접속부 형태와 재질에 따른 인공기저막의 진동거동 특성

김상원(Sang Won Kim),안상현(Sang Hyeon Ahn),박수아(Sua Park),정영도(Youngdo Jung),허신(Shin Hur),김완두(Wan Doo Kim) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

In order to transmit the vibration of ossicle to the input port of totally implantable artificial cochlear, a fluid-filled interface of tube shape is required. In order to investigate the vibratory transfer characteristic according to the material and shape of interface oscillation behavior of an artificial bailar membrane was measured and compared. The interface and artificial cochlear package were filled with phosphate buffered saline solution. Vibration signal was appiled to the entrance of interface by using piezo actuator. Vibratory characteristic of artificial cochlear membrane was analyzed by using laser Doppler vibrometer. Experiments were carried out without any interface and with interfaces; straight metal tube, straight plastic tube and curved plastic tube. Experimental results show that the measured magnitude of membrane vibration decreased in the order of the cases without a tube, with a metal tube, and with a plastic tube. The experimental results with straight plastic tube and curved plastic tube were similar.

Flexural Beam 형상에 따른 초음파 물체 부상 이송 시스템의 진동 특성

정상화(S. H. Jeong),신상문(S. M. Shin),김광호(G. H. Kim),이상희(S. H. Lee),김주환(J. H. Kim) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

Transport systems which are the important part of the factory automation have much influence on improving productivity. Object transport systems are driven typically by the magnetic field and conveyer belt. In recent years, as the transmission and processing of information is required more quickly, demands of optical elements and semiconductors increase. However, conventional transport systems are not adequate for transportation of those. The reason is that conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. Vibration modes of each flexural beam are verified by using Laser Scanning Vibrometer.

유한 너비 판에서 판파의 공간적 맥놀이 전파 거동 및 실험적 검증

박상진(Sang-Jin Park),주영상(Young-Sang Joo),김회웅(Hoe-Woong Kim),김성균(Sung-Kyun Kim),이제환(Jewhan Lee) 한국비파괴검사학회 2021 한국비파괴검사학회지 Vol.41 No.5

판파는 이론적으로 무한한 너비를 갖는 자유 상태의 평판에서 두께방향으로 모드(mode)를 형성하며 전파하는 유도파(guided wave)이다. 그러나 실제 적용에서 무한 너비 판은 존재할 수 없으며 대부분의 판 구조물들은 유한한 너비를 갖는다. 이러한 유한한 너비를 갖는 판 구조물에서의 판파는 엄밀하게 무한 너비 판에서의 판파와 다른 전파 특성을 가지며 판 두께 대비 너비 비율이 작아질수록 그 차이는 커진다. 특히, 유한 너비 판에서의 판파는 너비방향으로 추가적인 모드들을 형성하고, 형성된 너비방향 모드들은 모드 밀집도를 증가시킨다. 이로 인해 유한 너비 판에서는 단일 모드의 선택적 가진이 어려워지고 다중 모드들이 동시에 가진되며 이 모드들이 서로 중첩되어 전파할 수 있다. 본 연구에서는 유한 너비 판에서 다중 판파 모드들이 중첩되어 전파하며 나타나는 공간적 맥놀이 전파 거동을 전산적으로 분석하였으며, 레이저 스캐닝 변위계를 이용해 실험적으로 검증하였다. 결과적으로, 판파 전파 거동에 대한 전산 분석결과는 실험 결과와 잘 일치하였고, 유한 너비 판의 너비에 따라 판파의 공간적 맥놀이의 길이가 변화되는 것을 확인하였다. Theoretically, a Lamb wave is a guided wave that travels in a free flat plate with an infinite width, having thickness modes confined by the top and bottom boundaries. However, plates with infinite width do not exist in practical application and most plate structures have finite widths. In these plate structures with finite widths, the propagation characteristics of Lamb waves are extremely different from those in an infinite plate and the difference increases as the plate width gets narrower. Specifically, Lamb waves in a finite width plate form additional width modes confined by both lateral sides and the width modes lead to an increase in modal density. Consequently, it becomes more difficult to selectively excite a single Lamb wave mode, and multiple modes can be excited together and propagated with mode superposition. In this work, the propagation behavior of spatial beating caused by the mode superposition of the multiple Lamb wave modes in a finite width plate was numerically investigated and experimentally validated using a laser scanning vibrometer. The computational results on the propagation behavior of the Lamb waves agreed well with the experimental results, and it was validated that the spatial beating length of the Lamb waves varied with the plate width of the finite width plate.

탄성빔 형상의 변화에 따른 초음파 이송시스템의 진동 특성에 관한 연구

정상화(Sang Hwa Jeong),김광호(Gwang Ho Kim),신상문(Sang Moon Shin),이상희(Sang Hee Lee),김주환(Ju Hwan Kim) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-

Recently, the semiconductor industry as well as the optical industry such as the optical communication and the optical instrument is developed rapidly. Transport systems which are the important part of the factory automation have much influence on improving productivity. Object transport systems are driven typically by the magnetic field and the conveyer belt. In recent years, the industry requires faster and more efficient transport system. However, conventional transport systems are not adequate for transportation of optical elements and semiconductors. The reason is that conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. Vibration modes of each flexural beam are verified by using Laser Scanning Vibrometer.