TRIAXIAL FORCE MEASUREMENT CANTILEVER BYSIDEWALL-DOPING WITH RAPID THERMAL DIFFUSION

Yuichiro Aoyama, Nguyen Binh-Khiem, Kentaro Noda, Yusuke Takei, Tetsuo Kan,Eiji Iwase, Kiyoshi Matsumoto and Isao ShimoyamaThe University of Tokyo

Professor: Cheng-Hsien, LiuStudent: Hao-Ran, Shih (9933533)Date: 2010/11/16

Outline

ABSTRACT INTRODUCTION DESIGN OF THE CANTILEVER FABRICATION EXPERIMENTAL RESULTS CONCLUSION

ABSTRACT

a tool for applying quantitative mechanical stimuli to cells and measuring their mechanical properties at the same time

consists of a sensing tip, two sensing beams, , four wiring beams , and piezoresistors on the surface of the sensing tip

sensitivities of the device were 1.59×10-3 μm-1, 1.18×10-3 μm-1 and 3.26×10-4 μm-1 for x, y, and z-direction

INTRODUCTION

1.mechanical properties of biological samples：

angiotensin II (AngII)

2.AFM probe method and fluorescence microscopic observation：

these conventional approaches are unable to measure three dimensional (3D) quantities of forces and mechanical properties.

3.piezoresistive cantilever force sensor with dope-sites located on the cantilever surface：

measure only forces perpendicular to its cantilever surface

the white dashed line is the head designed to protect the cantilever

4.sidewall-doping method utilizing rapid thermal diffusion

In this paper, they fabricated the cantilever by

using both surface and sidewall doping. They measured the displacement sensitivities of the cantilever in three directions and confirmed that the device can measure triaxial forces.

DESIGN OF THE CANTILEVER

resistances1.ΔR1/R1 + ΔR2/R2 for x direction2.ΔR2/R2 - ΔR1/R1 for y direction3.R3 located on the surface of the sensing tip

FABRICATION

EXPERIMENTAL RESULTS

The electrical resistance of the piezoresistors R1, R2,and R3 in the fabricated cantilever were 34.2 kΩ, 31.4kΩ, and 10.8 kΩ.

For data of x direction,it showed an unexpected hysteresis characteristic. They estimate its hysteresis were due to the slippage of the pipette and the sensing tip.

CONCLUSION

1.fabricated a triaxial force measurement cantilever with piezoresistors fabricated by sidewall-doping with rapid thermal diffusion.

2.the device has three piezoresistors for measuring forces in x, y, and z direction. The displacement sensitivities in x, y, and z direction were 1.59×10-3 μm-1, 1.18×10-3 μm-1, and 3.26×10-4 μm-1, respectively.

3.confirmed that the cantilever was capable of measuring triaxial force and had a good linear characteristic.

4. in future work,demonstrate the use of their cantilever in measuring on biological samples.

REFERENCES

1.C-A. Lamontagne, et al., “AFM as a tool probe and manipulate cellular processes,” Pfluger Arch.-Eur. J. Physiol., vol. 456, pp. 61-70, 2008.

2.R. Silberberg, et al., “Mitochondrial displacements in response to nanomechanical forces,” J. Mol. Recognit., vol. 21, pp. 30-36,2008.

3.M. Gel, et al., “Force sensing sub-micrometer thick cantilevers with ultra-thin piezoresistors by rapid thermal diffusion,” J. Micromech.

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