# MEMS Device for Quantitative In Situ Mechanical Testing in Electron Microscope

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## Abstract

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## 1. Introduction

## 2. Mechanical Testing System

#### 2.1. Description of the System

_{a}and x

_{b}are the center deflections of beams A and B, respectively, and l

_{0}is the initial length of the specimen.

_{b}is the driving force acting on beam B and S is the cross-sectional area of the specimen. Using a push-to-pull structure, the external compressive stress on the specimen was transferred to a tensile stress, as shown in Figure 1b.

#### 2.2. Sensor Design

_{1}and R

_{2}, located at the roots of the beams A and B, measure the beam deflection. The resistances of the other two resistors, R

_{3}and R

_{4}, attached to the substrate, remain constant during the beam deflection. The four resistors are electrically connected with aluminum (Al) interconnects. To improve the consistency of the process and to partially compensate the influence of temperature, the resistors on the beam and those on the substrate were placed as close as possible to each other [52]. The beams and the piezoresistors are aligned along the <110> direction on the (100) plane of a silicon wafer substrate for obtaining a better sensor sensitivity [53].

_{l}and σ

_{t}are the longitudinal and transverse stresses, and π

_{l}and π

_{t}are the piezoresistance coefficients along the longitudinal and transverse directions. Since σ

_{t}is much smaller than σ

_{l}, the term ${\mathsf{\pi}}_{\mathrm{t}}{\mathsf{\sigma}}_{\mathrm{t}}$ can be neglected [51]. Figure 3 shows the positions of the piezoresistors on the beam and the parameters used in Equations (4) and (5). In the case of small deformation, the variance of the resistance can be written as:

_{p}is the piezoresistor length, ω is the beam center deflection, and d′ is the distance between the resistor centerline and neutral plane of the beam. The value d′ can be expressed as:

_{p}is the width of the piezoresistor, and d″ is the distance between the outer edge of the piezoresistor and the beam. Figure 3 shows all the parameters in Equation (5).

_{3}and R

_{4}have an equal resistance variance ΔR, the bridge output voltage is given as:

_{B}is the bridge bias voltage.

_{B}is the Boltzmann constant, T is the absolute temperature, N

_{p}is the dopant concentration, q is the amount of the carrier charge, μ

_{p}is the hole mobility, d

_{p}is the piezoresistor thickness, α is a non-dimensional fitting parameter depending on the annealing conditions, and f

_{max}and f

_{min}are the upper and lower measurement frequency limits. The displacement resolution of the sensors is defined as the ratio of the noise to the displacement sensitivity (only considering Johnson and 1/f noise), and can be written as:

_{p}). For a nearly constant d″, depending on the MEMS technology, the d′ will become shorter when w

_{p}is increased, leading to a decrease in the displacement sensitivity. To obtain an optimal width (w

_{p-optimal}), the resolution R

_{D}can be partially differentiated against the piezoresistor width. The optimal width thus obtained is:

_{p}, of the piezoresistor has an opposite influence on the power density of the Hooge and Johnson noises, i.e., a decrease in the Hooge noise but an increase in the Johnson noise. It is further noted from Equation (7) that increase in l

_{p}can also lead to a loss in the displacement sensitivity. Because of the complicated effect of l

_{p}on the displacement resolution and sensitivity, the resolution was partially differentiated against l

_{p}to obtain an optimal length contributing to a high resolution. For each clamped beam length, L, an optimal l

_{p-optimal}is obtained. Figure 4 shows the evolution of l

_{p-optimal}/L as a function of the clamped beam length. The results show that the l

_{p-optimal}/L decreases with increasing L.

## 3. Experiment

#### 3.1. Fabrication Process

_{2}insulation layer was grown on each side of the wafer by thermal oxidation (Figure 5a). The thermal oxidation SiO

_{2}layer on the device side was patterned and etched as a mask for subsequent ion implantation. The piezoresistors, with resistivity of $1.17\times {10}^{-2}$ Ω·cm, were prepared by boron doping by means of ion implantation at 100 keV with a dose of ${10}^{15}$ ${\mathrm{cm}}^{-2}$ (p-doped, Figure 5b). Using the same process, electrical contacts were created with an implantation energy of 100 keV and a dose of $3\times {10}^{15}$ ${\mathrm{cm}}^{-2}$ (p+ doped, Figure 5c). A 1-μm-thick aluminum film was then sputtered on the surface and then etched using potassium hydroxide (KOH) solution to form interconnects and pads (Figure 5d). The device layer was then etched by inductively coupled plasma (ICP) etching (Figure 5e). Finally, ICP was used to etch out the handle and buried oxide layers from the backside to create a movable structure (Figure 5f). Figure 6a shows a SEM image of a MEMS fabricated device. Figure 6b shows a magnified view of sensor B. The corresponding lithography maps are shown in Figure 6c,d. Comparison between the fabricated device and the lithography maps shows that the lateral undercutting of both ICP etching and aluminum film wet etching was less than 1 μm, indicating a well-controlled etching processes.

#### 3.2. Device Calibration and Quantitative Tensile Testing

_{a}and x

_{b}) based on the calibration. The deformation strain is then calculated according to Equation (1) by knowing the original length (l

_{0}) of the specimen prior to testing. The force applied on the specimen (F

_{b}) is calculated based on the displacement of beam B, as per Equation (16). The stress can then be calculated using Equation (2) by measuring the cross-sectional area (S) of the specimen prior to tensile testing.

#### 3.3. Specimen Preparation

## 4. Results and Discussion

#### 4.1. Sensors Performance

#### 4.2. Stress–Strain Curve

## 5. Conclusions

- (1)
- Sensors A and B have displacement sensitivities of 37.4 μV/nm and 4.8 μV/nm.
- (2)
- Sensor A has a theoretical displacement resolution of 0.19 nm and sensor B has a force resolution of 2.1 μN.
- (3)
- The MEMS device has a displacement range limit of 5.47 μm and a theoretical load range limit of 55.0 mN.
- (4)
- Measurement of the Young’s modulus of the Al film by the device verifies the reliability of the sensors.
- (5)
- The device has a dimension small enough to be integrated on the TEM holder to study the property–structure correlation at the atomic scale.

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

- Arzt, E. Size effects in materials due to microstructural and dimensional constraints: A comparative review. Acta Mater.
**1998**, 46, 5611–5626. [Google Scholar] [CrossRef] - Tsuchiya, T.; Tabata, O.; Sakata, J.; Taga, Y. Specimen size effect on tensile strength of surface-micromachined polycrystalline silicon thin films. J. Microelectromech. Syst.
**1998**, 7, 106–113. [Google Scholar] [CrossRef] - Namazu, T.; Isono, Y.; Tanaka, T. Evaluation of size effect on mechanical properties of single crystal silicon by nanoscale bending test using AFM. J. Microelectromech. Syst.
**2000**, 9, 450–459. [Google Scholar] [CrossRef] - Sharpe, W.N.; Jackson, K.M.; Hemker, K.J.; Xie, Z. Effect of specimen size on Young’s modulus and fracture strength of polysilicon. J. Microelectromech. Syst.
**2001**, 10, 317–326. [Google Scholar] [CrossRef] - Uchic, M.D.; Dimiduk, D.M.; Florando, J.N.; Nix, W.D. Sample dimensions influence strength and crystal plasticity. Science
**2004**, 305, 986–989. [Google Scholar] [CrossRef] [PubMed] - Greer, J.R.; Oliver, W.C.; Nix, W.D. Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater.
**2005**, 53, 1821–1830. [Google Scholar] [CrossRef] - Parthasarathy, T.A.; Rao, S.I.; Dimiduk, D.M.; Uchic, M.D.; Trinkle, D.R. Contribution to size effect of yield strength from the stochastics of dislocation source lengths in finite samples. Scr. Mater.
**2007**, 56, 313–316. [Google Scholar] [CrossRef] - Greer, J.R.; De Hosson, J.T.M. Plasticity in small-sized metallic systems: Intrinsic versus extrinsic size effect. Prog. Mater. Sci.
**2011**, 56, 654–724. [Google Scholar] [CrossRef] - Han, X.D.; Zhang, Y.F.; Zheng, K.; Zhang, X.N.; Zhang, Z.; Hao, Y.J.; Guo, X.Y.; Yuan, J.; Wang, Z.L. Low-temperature in situ large strain plasticity of ceramic SiC nanowires and its atomic-scale mechanism. Nano Lett.
**2007**, 7, 452–457. [Google Scholar] [CrossRef] [PubMed] - Han, X.D.; Zheng, K.; Zhang, Y.F.; Zhang, X.N.; Zhang, Z.; Wang, Z.L. Low-temperature in situ large-strain plasticity of silicon nanowires. Adv. Mater.
**2007**, 19, 2112–2118. [Google Scholar] [CrossRef] - Zhang, Y.F.; Han, X.D.; Zheng, K.; Zhang, Z.; Zhang, X.N.; Fu, J.Y.; Ji, Y.; Hao, Y.J.; Guo, X.Y.; Wang, Z.L. Direct observation of super-plasticity of beta-SiC nanowires at low temperature. Adv. Funct. Mater.
**2007**, 17, 3435–3440. [Google Scholar] [CrossRef] - Zheng, K.; Han, X.D.; Wang, L.H.; Zhang, Y.F.; Yue, Y.H.; Qin, Y.; Zhang, X.N.; Zhang, Z. Atomic mechanisms governing the elastic limit and the incipient plasticity of bending Si nanowires. Nano Lett.
**2009**, 9, 2471–2476. [Google Scholar] [CrossRef] [PubMed] - Zheng, K.; Wang, C.C.; Cheng, Y.Q.; Yue, Y.H.; Han, X.D.; Zhang, Z.; Shan, Z.W.; Mao, S.X.; Ye, M.M.; Yin, Y.D.; et al. Electron-beam-assisted superplastic shaping of nanoscale amorphous silica. Nat. Commun.
**2010**, 1, 24. [Google Scholar] [CrossRef] [PubMed] - Yue, Y.H.; Liu, P.; Zhang, Z.; Han, X.D.; Ma, E. Approaching the theoretical elastic strain limit in copper nanowires. Nano Lett.
**2011**, 11, 3151–3155. [Google Scholar] [CrossRef] [PubMed] - Li, H.X.; Mao, S.C.; Zang, K.T.; Liu, Y.; Guo, Z.X.; Wang, S.B.; Zhang, Y.F.; Yin, X.Q. An in situ TEM study of the size effect on the thermally induced martensitic transformation in nanoscale NiTi shape memory alloy. J. Alloy. Compd.
**2014**, 588, 337–342. [Google Scholar] [CrossRef] - Mao, S.C.; Li, H.X.; Liu, Y.; Deng, Q.S.; Wang, L.H.; Zhang, Y.F.; Zhang, Z.; Han, X.D. Stress-induced martensitic transformation in nanometric NiTi shape memory alloy strips: An in situ TEM study of the thickness/size effect. J. Alloy. Compd.
**2013**, 579, 100–111. [Google Scholar] [CrossRef] - Han, X.D.; Wang, L.H.; Yue, Y.H.; Zhang, Z. In situ atomic scale mechanical microscopy discovering the atomistic mechanisms of plasticity in nano-single crystals and grain rotation in polycrystalline metals. Ultramicroscopy
**2015**, 151, 94–100. [Google Scholar] [CrossRef] [PubMed] - Wang, L.; Teng, J.; Liu, P.; Hirata, A.; Ma, E.; Zhang, Z.; Chen, M.; Han, X. Grain rotation mediated by grain boundary dislocations in nanocrystalline platinum. Nat. Commun.
**2014**, 5, 4402. [Google Scholar] [CrossRef] [PubMed] - Wang, L.H.; Zheng, K.; Zhang, Z.; Han, X.D. Direct Atomic-scale imaging about the mechanisms of ultralarge bent straining in Si nanowires. Nano Lett.
**2011**, 11, 2382–2385. [Google Scholar] [CrossRef] [PubMed] - Yue, Y.H.; Liu, P.; Deng, Q.S.; Ma, E.; Zhang, Z.; Han, X.D. Quantitative evidence of crossover toward partial dislocation mediated plasticity in copper single crystalline nanowires. Nano Lett.
**2012**, 12, 4045–4049. [Google Scholar] [CrossRef] [PubMed] - Wang, L.H.; Zhang, Z.; Han, X.D. In situ experimental mechanics of nanomaterials at the atomic scale. NPG Asia Mater.
**2013**, 5, e40. [Google Scholar] [CrossRef] - Wang, L.H.; Han, X.D.; Liu, P.; Yue, Y.H.; Zhang, Z.; Ma, E. In situ observation of dislocation behavior in nanometer grains. Phys. Rev. Lett.
**2010**, 105, 478–481. [Google Scholar] [CrossRef] [PubMed] - Jiang, Q.K.; Liu, P.; Ma, Y.; Cao, Q.P.; Wang, X.D.; Zhang, D.X.; Han, X.D.; Zhang, Z.; Jiang, J.Z. Super elastic strain limit in metallic glass films. Sci. Rep. UK
**2012**, 2, 852. [Google Scholar] [CrossRef] [PubMed] - Wang, L.; Wang, X.D.; Mao, S.C.; Wu, H.; Guo, X.; Ji, Y.; Han, X.D. Strongly enhanced ultraviolet emission of an Au@SiO
_{2}/ZnO plasmonic hybrid nanostructure. Nanoscale**2016**, 8, 4030–4036. [Google Scholar] [CrossRef] [PubMed] - Kong, D.L.; Sun, S.D.; Xin, T.J.; Xiao, L.R.; Sha, X.C.; Lu, Y.; Mao, S.C.; Zou, J.; Wang, L.H.; Han, X.D. Reveal the size effect on the plasticity of ultra-small sized Ag nanowires with in situ atomic-scale microscopy. J. Alloy. Compd.
**2016**, 676, 377–382. [Google Scholar] [CrossRef] - Zang, K.T.; Mao, S.C.; Cai, J.X.; Liu, Y.N.; Li, H.X.; Hao, S.J.; Jiang, D.Q.; Cui, L.S. Revealing ultralarge and localized elastic lattice strains in Nb nanowires embedded in NiTi matrix. Sci. Rep. UK
**2015**, 5, 17530. [Google Scholar] [CrossRef] [PubMed] - Zhu, Y.; Ke, C.; Espinosa, H.D. Experimental techniques for the mechanical characterization of one-dimensional nanostructures. Exp. Mech.
**2007**, 47, 7–24. [Google Scholar] [CrossRef] - Wang, B.; Tomar, V.; Haque, A. In-situ TEM mechanical testing of nanocrystalline zirconium thin films. Mater. Lett.
**2015**, 152, 105–108. [Google Scholar] [CrossRef] - Huang, L.; Li, Q.-J.; Shan, Z.-W.; Li, J.; Sun, J.; Ma, E. A new regime for mechanical annealing and strong sample-size strengthening in body centred cubic molybdenum. Nat. Commun.
**2011**, 2, 547. [Google Scholar] [CrossRef] [PubMed] - Edwards, R.L.; Coles, G.; Sharpe, W.N. Comparison of tensile and bulge tests for thin-film silicon nitride. Exp. Mech.
**2004**, 44, 49–54. [Google Scholar] [CrossRef] - Majjad, H.; Basrour, S.; Delobelle, P.; Schmidt, M. Dynamic determination of Young’s modulus of electroplated nickel used in LIGA technique. Sens. Actuators A Phys.
**1999**, 74, 148–151. [Google Scholar] [CrossRef] - Dzung Viet, D.; Koichi, N.; Tung Thanh, B.; Susumu, S. Micro/nano-mechanical sensors and actuators based on SOI-MEMS technology. Adv. Nat. Sci. Nanosci. Nanotechnol.
**2010**, 1, 013001. [Google Scholar] - Rui, L.; Hong, W.; Xueping, L.; Guifu, D.; Chunsheng, Y. A micro-tensile method for measuring mechanical properties of MEMS materials. J. Micromech. Microeng.
**2008**, 18, 065002. [Google Scholar] - Warren, O.L.; Shan, Z.; Asif, S.A.S.; Stach, E.A.; Morris, J.W., Jr.; Minor, A.M. In situ nanoindentation in the TEM. Mater. Today
**2007**, 10, 59–60. [Google Scholar] [CrossRef] - Bobji, M.S.; Ramanujan, C.S.; Pethica, J.B.; Inkson, B.J. A miniaturized TEM nanoindenter for studying material deformation in situ. Meas. Sci. Technol.
**2006**, 17, 1324. [Google Scholar] [CrossRef] - Pharr, G.M. Measurement of mechanical properties by ultra-low load indentation. Mater. Sci. Eng. A
**1998**, 253, 151–159. [Google Scholar] [CrossRef] - Wei, Y.; Hutchinson, J.W. Hardness trends in micron scale indentation. J. Mech. Phys. Solids
**2003**, 51, 2037–2056. [Google Scholar] [CrossRef] - Bucaille, J.L.; Stauss, S.; Felder, E.; Michler, J. Determination of plastic properties of metals by instrumented indentation using different sharp indenters. Acta Mater.
**2003**, 51, 1663–1678. [Google Scholar] [CrossRef] - Alkorta, J.; Martínez-Esnaola, J.M.; Gil Sevillano, J. Detailed assessment of indentation size-effect in recrystallized and highly deformed niobium. Acta Mater.
**2006**, 54, 3445–3452. [Google Scholar] [CrossRef] - Arsenlis, A.; Parks, D.M. Crystallographic aspects of geometrically-necessary and statistically-stored dislocation density. Acta Mater.
**1999**, 47, 1597–1611. [Google Scholar] [CrossRef] - Busso, E.P.; Meissonnier, F.T.; O’Dowd, N.P. Gradient-dependent deformation of two-phase single crystals. J. Mech. Phys. Solids
**2000**, 48, 2333–2361. [Google Scholar] [CrossRef] - Pantano, M.F.; Espinosa, H.D.; Pagnotta, L. Mechanical characterization of materials at small length scales. J. Mech. Sci. Technol.
**2012**, 26, 545–561. [Google Scholar] [CrossRef] - Kumar, S.; Alam, T.; Haque, A. Quantitative in-situ TEM study of stress-assisted grain growth. MRS Commun.
**2013**, 3, 101–105. [Google Scholar] [CrossRef] - Haque, M.A.; Espinosa, H.D.; Lee, H.J. MEMS for in situ testing—Handling, actuation, loading, and displacement measurements. MRS Bull.
**2010**, 35, 375–381. [Google Scholar] [CrossRef] - Han, J.H.; Saif, M.T.A. In situ microtensile stage for electromechanical characterization of nanoscale freestanding films. Rev. Sci. Instrum.
**2006**, 77, 045102. [Google Scholar] [CrossRef] - Jin, Q.H.; Li, T.; Wang, Y.L.; Li, X.X.; Zhou, P.; Xu, F.F. In-situ TEM tensile test of 90nm-thick SCS beam using MEMS chip. Sens. IEEE
**2008**. [Google Scholar] [CrossRef] - Yu, S.; Bradley, J.N. MEMS capacitive force sensors for cellular and flight biomechanics. Biomed. Mater.
**2007**, 2, S16. [Google Scholar] - Dongfeng, Z.; Breguet, J.M.; Clavel, R.; Sivakov, V.; Christiansen, S.; Michler, J. In situ electron microscopy mechanical testing of silicon nanowires using electrostatically actuated tensile stages. J. Microelectromech. Syst.
**2010**, 19, 663–674. [Google Scholar] [CrossRef] - Barlian, A.A.; Woo-Tae, P.; Mallon, J.R.; Rastegar, A.J.; Pruitt, B.L. Review: Semiconductor piezoresistance for microsystems. Proc. IEEE
**2009**, 97, 513–552. [Google Scholar] [CrossRef] [PubMed] - Tortonese, M.; Barrett, R.C.; Quate, C.F. Atomic resolution with an atomic force microscope using piezoresistive detection. Appl. Phys. Lett.
**1993**, 62, 834–836. [Google Scholar] [CrossRef] - Duc, T.C.; Creemer, J.F.; Sarro, P.M. Lateral nano-Newton force-sensing piezoresistive cantilever for microparticle handling. J. Micromech. Microeng.
**2006**, 16, S102. [Google Scholar] [CrossRef] - Chui, B.W.; Aeschimann, L.; Akiyama, T.; Staufer, U.; de Rooij, N.F.; Lee, J.; Goericke, F.; King, W.P.; Vettiger, P. Advanced temperature compensation for piezoresistive sensors based on crystallographic orientation. Rev. Sci. Instrum.
**2007**, 78, 043706. [Google Scholar] [CrossRef] [PubMed] - Smith, C.S. Piezoresistance effect in germanium and silicon. Phys. Rev.
**1954**, 94, 42–49. [Google Scholar] [CrossRef] - Kanda, Y. Piezoresistance effect of silicon. Sens. Actuators A Phys.
**1991**, 28, 83–91. [Google Scholar] [CrossRef] - Taechung, Y.; Chang-Jin, K. Measurement of mechanical properties for MEMS materials. Meas. Sci. Technol.
**1999**, 10, 706. [Google Scholar] - Harkey, J.A.; Kenny, T.W. 1/f noise considerations for the design and process optimization of piezoresistive cantilevers. J. Microelectromech. Syst.
**2000**, 9, 226–235. [Google Scholar] [CrossRef] - Nash, W.A. Schaum’s Outline of Theory and Problems of Strength of Materials, 4th ed.; McGraw-Hill: New York, NY, USA, 1998. [Google Scholar]
- Nakladal, A.; Sager, K.; Gerlach, G. Influences of humidity and moisture on the long-term stability of piezoresistive pressure sensors. Measurement
**1995**, 16, 21–29. [Google Scholar] [CrossRef] - Hoa, P.L.P.; Suchaneck, G.; Gerlach, G. Influence of polycrystalline silicon as electrical shield on reliability and stability of piezoresistive sensors. Sens. Actuators A Phys.
**2005**, 120, 567–572. [Google Scholar] [CrossRef] - Park, S.J.; Doll, J.C.; Pruitt, B.L. Piezoresistive cantilever performance-part I: Analytical model for sensitivity. J. Microelectromech. Syst.
**2010**, 19, 137–148. [Google Scholar] [CrossRef] [PubMed] - Rob, L.; Groeneveld, A.W.; Elwenspoek, M. Comb-drive actuators for large displacements. J. Micromech. Microeng.
**1996**, 6, 320. [Google Scholar] - Haque, M.A.; Saif, M.T.A. Application of MEMS force sensors for in situ mechanical characterization of nano-scale thin films in SEM and TEM. Sens. Actuators A Phys.
**2002**, 97–98, 239–245. [Google Scholar] [CrossRef]

**Figure 1.**Schematic of the testing system in scanning electron microscopes (SEM): (

**a**) the actuation control flow chart; and (

**b**) design of the testing apparatus.

**Figure 3.**Schematic of the piezoresistor beam positions and the parameters used in Equations (4) and (5).

**Figure 5.**Schematic of the main steps to fabricate the MEMS device: (

**a**) thermal oxidation; (

**b**) p− doped; (

**c**) p+ doped and contact hole; (

**d**) interconnects and pads; (

**e**) front side inductively coupled plasma (ICP); and (

**f**) structure release.

**Figure 6.**MEMS device with piezoresistive sensors: (

**a**) SEM image of the device; (

**b**) enlarged SEM image of the sensor B region; (

**c**) lithography map of the device; and (

**d**) lithography map of the sensor B region.

**Figure 7.**Setup for in situ tensile testing in SEM: (

**a**) the optical image of the testing system equipped in SEM; and (

**b**) schematic of the testing system.

**Figure 11.**Displacement calibrations of sensors in SEM: (

**a**–

**f**) the displacements of the two reference points for sensor A; and (

**g**–

**l**) their displacements for sensor B.

Parameters | Value | Unit | |
---|---|---|---|

Sensor A | Sensor B | ||

Α | 10^{−5} | - | |

T | 300 | K | |

μ_{p} | 0.934 × 10^{−2} | cm^{2}·V^{−1}·s^{−1} | |

Bias voltage | 3.0 | V | |

f_{max} | 1000 | Hz | |

f_{min} | 10 | Hz | |

Clamped beam length | 150 | 600 | Μm |

Clamped beam width | 60 | 60 | Μm |

Clamped beam thickness | 30 | 15 | Μm |

Piezoresistor length | 46 | 107 | Μm |

Piezoresistor width | 8 | 3 | Μm |

Piezoresistor thickness | 1.1 | 1.1 | Μm |

Theoretical displacement sensitivity | 77.1 | 7.1 | μV/nm |

Theoretical displacement resolution | 0.19 | 4.6 | nm |

Theoretical displacement range limit | 5.47 | 175.14 | μm |

Theoretical load range limit | 888 | 55.0 | mN |

Length (nm) | Width (nm) | Depth (nm) |
---|---|---|

4880 | 620 | 510 |

Sensors | Magnification | ||
---|---|---|---|

2000× | 8000× | 16,000× | |

Sensor A | 37.5 μV/nm | 37.2 μV/nm | 37.4 μV/nm |

Sensor B | 4.6 μV/nm | 4.9 μV/nm | 4.8 μV/nm |

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## Share and Cite

**MDPI and ACS Style**

Wang, X.; Mao, S.; Zhang, J.; Li, Z.; Deng, Q.; Ning, J.; Yang, X.; Wang, L.; Ji, Y.; Li, X.;
et al. MEMS Device for Quantitative In Situ Mechanical Testing in Electron Microscope. *Micromachines* **2017**, *8*, 31.
https://doi.org/10.3390/mi8020031

**AMA Style**

Wang X, Mao S, Zhang J, Li Z, Deng Q, Ning J, Yang X, Wang L, Ji Y, Li X,
et al. MEMS Device for Quantitative In Situ Mechanical Testing in Electron Microscope. *Micromachines*. 2017; 8(2):31.
https://doi.org/10.3390/mi8020031

**Chicago/Turabian Style**

Wang, Xiaodong, Shengcheng Mao, Jianfei Zhang, Zhipeng Li, Qingsong Deng, Jin Ning, Xudong Yang, Li Wang, Yuan Ji, Xiaochen Li,
and et al. 2017. "MEMS Device for Quantitative In Situ Mechanical Testing in Electron Microscope" *Micromachines* 8, no. 2: 31.
https://doi.org/10.3390/mi8020031