Showing papers presented at "International Conference on Nanotechnology in 2007"

Spin-MTJ based Non-volatile Flip-Flop

Abstract: Spin Transfer Torque (STT) writing approach based Magnetic Tunnel Junction (Spin-MTJ) is the excellent candidate to be used as Spintronics device in Magnetic RAM (MRAM) and Magnetic Logic. We present the first Non-volatile Flip-Flop based on this device for Field Programmable Gate Array (FPGA) and System On Chip (SOC) circuits, which can make these circuits fully non-volatile by storing permanently all the data processed in the Spin-MTJ memory cells. The non-volatility enables logic circuits to decrease significantly the start-up latency of these circuits from some micro seconds down to some hundred pico seconds. By using St microelectronics 90 nm CMOS technology and a behavior Spin-MTJ simulation Model in Verilog-A language, this non-volatile Flip-Flop has been demonstrated that it works not only in very high speed or low propagation delay, but also keeps low power dissipation and small cell surface.

Study of piezoresistance effect of carbon nanotube-PDMS composite materials for nanosensors

Abstract: Samples of novel nanocomposites of multiwalled carbon nanotube and poly (dimethylsiloxane), i.e., CNT-PDMS, at different filler concentrations are prepared. The mechanical/electrical and piezoresistance properties of these nanomaterials are studied in detail. The gauge factor (GF) of this nanocomposite, dependent on the content of CNT, ranges from 1.38 to 12.4. Since the CNT-PDMS can be easily used as a novel piezoresistor using low-cost MEMS technology, this nanomaterial has decent potential in nanosensors and PDMS-based microfluidic systems.

Synthesis of (AgIn) x Cd 2(1-x) S 2 Photocatalysts for H 2 Evolution under Visible Light by Using a Low-temperature Hydrothermal Method

Abstract: We present a new visible-light driven photocatalyst (AgIn)xCd2(1-x)S2 prepared by low-temperature hydrothermal method. Here, (AgIn)xCd2(1-x)S2 with nanostructure shows photocatalytic activities for H2 evolution from aqueous solutions containing sacrificial reagents, SO3 2- and S2- under visible-light irradiation even without any cocatalysts. The morphology and band gap of the photocatalysts are different with x changing from 0.01 to 0.5, and the band gap of (AgIn)xCd2(1-x)S2 can be easily tuned from 2.32-2.08 eV. Importantly, the addition of Ag+ and In3+ ion to CdS can improve the light sensitization of photocatalyst. (AgIn)0.05Cd1.9S2 with a 2.29 eV band gap has good photocatalytic activity for H2 evolution under visible light irradiation even without a Pt cocatalyst (274.5 mumol g-1h-1 ), The photocatalytic activity (1172.3 mumol g-1h-1 ) of the same sample loaded with Pt cocatalyst is much higher than that of Pt-loaded CdS (40.2 mumol g-1h-1).

Real-time rigid-body visual tracking in a scanning electron microscope

Abstract: Robotics continues to provide researchers with an increasing ability to interact with objects at the nano scale. As micro- and nanorobotic technologies mature, more interest is given to computer-assisted or automated approaches to manipulation at these scales. Although actuators are currently available that enable displacements resolutions in the subnanometer range, improvements in feedback technologies have not kept pace. Thus, many actuators that are capable of performing nanometer displacements are limited in automated tasks by the lack of suitable feedback mechanisms. This paper proposes the use of a rigid-model-based method for end effector tracking in a scanning electron microscope to aid in enabling more precise automated manipulations and measurements. These models allow the system to leverage domain-specific knowledge to increase performance in a challenging tracking environment.

RC circuit model for multi-walled carbon nanotubes

Abstract: To alleviate the problems associated with current copper interconnect technology, multi-walled carbon nanotubes (MWCNTs) have been proposed as a potential solution for on-chip communication in VLSI applications. In this paper, we develop an equivalent RC circuit model for MWCNT interconnect that captures both DC conductance and high frequency impedance due to capacitive effects. Based on the circuit model, we find that MWCNT-based interconnect can have substantially less delay than copper wires in global interconnect applications.

Hardware architecture for nanorobot application in cerebral aneurysm

Abstract: This paper presents an innovative hardware architecture for medical use of nanorobots proposed as an advanced and precise tool for brain aneurysm instrumentation and diagnosis. The feasibility of the outlined architecture is supported by nanobioelectronics, clinical data, and wireless technologies, as embedded integrated system devices for molecular machine data transmission and control upload. The upcoming therapeutic possibility of using nanorobots for aneurysm treatments is the natural result from some recent developments and trends in nanoelectronics, wireless communication, remote power transmission, quantum dots, nanotubes, SOI, lithography, biomedical instrumentation, genome mapping, and photonics. To illustrate the proposed approach, we applied advanced 3D simulation techniques as a practical choice on methodology for medical nanorobotics architecture and integrated system prototyping.

Single carbon nanotube based photodiodes for infrared detection

Abstract: The photobehavior of carbon nanotubes (CNTs) has attracted great attention because of their unique cylinder structure and outstanding electrical properties. Much experimental progress toward nanotubes based photodetector has been reported. But it is still unclear whether the photoinduced conductivity change is caused by heating effect or quantum effect for the reported results. Moreover, the sensitivity of the CNT based IR detector needs to be further improved for real applications. In this paper, a single carbon nanotube based photodiode for infrared (IR) detection is constructed by assembling a single CNT to form connections with a pair of electrodes. By forming Schottky contact with an electrode, a semiconductive CNT is assembled into a Schottky diode. The photogenerated electron-hole pairs within the Schottky barrier are separated by an external electric field or the built-in field, producing a photocurrent. Since a semiconductive CNT normally forms Schottky contacts with both electrodes, the photocurrents generated by the two reversely connected Schottky diodes will cancel each other. Experimental results show that, at zero bias, the photocurrent varied from positive to negative as the IR spot center was moved from one electrode to another one. This proved that the photocurrent is caused by the photovoltaic effect in stead of the heating effect. To optimize the performance of the detector, a heterogeneous electrodes structure is designed to maximize the difference between the photocurrents of the two Schottky barriers. Different contact metals are selected such as an Ohmic contact is formed at one electrode and a Schottky barrier is formaed at another electrode. Experimental results show that the signal to dark current ratio of a heterogeneous detector is thousand times higher than the ratio of a homogeneous detector.

Clocking scheme for nanomagnet QCA

Abstract: Quantum-dot Cellular Automata (QCA) was previously demonstrated using aluminum tunnel junction single-electron transistor technology at mK temperatures, and molecular QCA is under development for operation at room temperature (RT). All of the basic building blocks needed for QCA have been experimentally demonstrated. Our work on nanomagnet-based QCA (NMQCA) holds the most promise for achieving viable RT operation in the near term. One requirement of the QCA architecture is a low-power clock structure. In this paper, we demonstrate the design and simulation of an on-chip low-power clock circuit that can facilitate the realization of the nanomagnet-based fully functional logic circuit on a single chip.

In-situ single cell mechanical characterization of W303 Yeast cells inside Environmental-SEM

Abstract: We present the environmental-SEM (ESEM)-nanomanipulator system for in-situ measurement of mechanical properties of the yeast cells (W303 strain). This enhanced ESEM system comprises of a standard ESEM instrument as a nano imaging tool, a cooling stage as a cellular biology's humidity controller and 7 D.O.F. linear actuators as nanomanipulator/effector. Two types of experiments have been conducted, i.e. mechanical properties of individual yeast cells and forces on cell-substrate area. Different kinds of spring constants (0.02 N/m, 0.09 N/m and 0.7 N/m) and tip's shapes (sharp, flat and needle-like) of the cantilevers have been used during the experiments. From the analysis, the compressed forces needed to penetrate the cell wall of the yeast cells using sharp and flat tips (0.02 N/m for both) are in the range of 87-278 nN and 57-207 nN respectively. Locality mechanical measurement has been performed using needle-like tip (0.09 N/m) on single-cell and mother-daughter cells where the elastic properties of the cells are in the range of 1.32-3.95 MPa. In addition to the above data, we have also investigated forces on cell-substrate area which can be divided into noncontact and contact forces. Under noncontact forces, average electrostatic forces between Au tip-Al substrate and tip-cell surfaces are measured to be 16 plusmn 2 nN and 5 plusmn 2 nN respectively. While under contact forces, two types of surface adhesions are measured which are cantilever's tip-wet surface adhesion and cell-surface adhesion where the release forces for each adhesion are 1107 plusmn 129 nN and 26578 nN respectively.

Quartz Crystal Microbalance humidity sensor using electrospun PANI micro/nano dots

Abstract: In this work, electrospun polyaniline (PANI) micro/nano dots on quartz crystal microbalance (QCM) sensor were used to sense the humidity at room temperature. A QCM humidity sensor is made by coating a low-cost commercial quartz crystal resonator with Polyaniline (PANI), which is one of the most promising polymers for sensing applications due to its relatively high stability. The electrospinning technique is used to coat the PANI nanometer-scale thin film to the electrode of quartz crystal. From experimental results, it was found that PANI coating on the QCM electrode is an effective way to improve humidity-sensing characteristic of QCM sensor. The PANI coated sensor has good response to the humidity with short response and recovery times. The experimental results show that the humidity sensitivity of PANI coated QCM sensor considerably depends on the thickness of PANI layer coated on the sensor electrode.

Electrospun nanofibrous membrane for air filtration

Abstract: Nanofibers have a large potential in air filtration applications, so this paper explores the performance of electrospun nanofiber membrane compared to traditional filtration fabrics. Poly (ethylene oxide) (PEO) and Polyvinyl Alcohol (PVA) were electrospun into nanofibrous membranes and analyzed their filtration attributes. Experimentation revealed that nanofibrous membranes have higher filtration efficiency than traditional filtration fabrics, such as meltblown and needle filtration material. In addition, nanofibrous membranes under the same electrospinning process but with different materials had similar high filtration efficiency, while their permeability had obvious difference. We suggest that different structure in the nanofiber membrane should cause this difference. Our work proves that there is a large potential for nanofiber membranes to utilize in air filtration area.

A fresh look at majority multiplexing when devices get into the picture

Abstract: In this paper we present the first detailed analysis of von Neumann multiplexing (vN-MUX) using majority (MAJ) gates of small fan-ins Delta (MAJ-Delta) with respect to the probability of failure of the elementary (nano-)devices. Only gates with small fan-ins have been considered, as gates with large fan-ins do not seem practical (at least in the short term) in future technologies. The extensions from an exact counting algorithm (for gate defects and faults only) to device-level failures will allow us to estimate and characterize MAJ-Delta vN-MUX with respect to device-level malfunctions. The reported results depart significantly from all known gate-level analyses-either theoretical or based on simulations. These should be quite important as providing a detailed picture of the behavior of MAJ-Delta vN-MUX when considering the (unreliability of the elementary) (nano-)devices (as opposed to gate-level only analyses). The main conclusion is that small fan-in gates (and redundancy schemes relying on such gates) are quite promising-in spite of all previous results at gate-level showing the contrary.

Deposition of Magnetite Nanoparticles in Activated Carbons and Preparation of Magnetic Activated Carbons

Abstract: Magnetic activated carbons (MACs) for gold recovery from alkaline cyanide solutions have been developed by mixing a magnetic precursor with a carbon source, and treating the mixture under controlled conditions. As would be expected, these activated carbons have high specific surface areas due to their microporous structure. In addition, the small particle size of the MACs produced allows rapid adsorption of gold in solution, and the magnetic character of these MACs enables recovery from suspension by magnetic separation.

Fault tolerant structures for nanoscale gates

Abstract: Predicted device reliability for nanoelectronics indicates that redundant design will be necessary to build reliable nanosystems. Up to date, several fault tolerant techniques have been proposed and analyzed. However, the fabrication complexity of those circuits, which directly affects the final circuit reliability, is not usually considered. In this paper, we compare two fault tolerant techniques, NAND Multiplexing (NM) and Averaging Cells (AC), as possible solutions to improve the nanoscale gate reliability. First, we propose nanodevice specific layouts for the two techniques. Then, we introduce nanotechnology oriented models to evaluate the area cost and reliability of the gates. Our simulations indicate that NM based gates are more reliable than AC gates when the error probabilities of the circuit parts are lower than 0.003. However, when this value is exceeded (which is expected for electronic nanotechnologies) AC gates are more reliable at a lower area cost.

Effective thermal conductivities and viscosities of water-based nanofluids containing Al2O3 with low concentration

Abstract: We experimentally investigated effective thermal conductivities and viscosities of water-based nanofluids containing Al2O3 (Al2O3-nanofluids) with low concentration from vol. 0.01% to 0.3%. Without surfactant, Al2O3-nanofluids are manufactured by two-step method which is widely used. To examine suspension and dispersion characteristics of Al2O3-nanofluids, zeta potential as well as transmission electron micrograph of Al2O3 nanoparticles is observed. The effective viscosities of Al2O3-nanofluids according to the temperature are measured by a viscometer of oscillating type. The transient hot wire method is used in this study to measure the effective thermal conductivities of Al2O3-nanofluids. Based on the results the maximum increase of effective viscosities of Al2O3-nanofluids is up to 2.9% while the maximum enhancement of effective thermal conductivities is up to 1.44%.

Quantum cryptography: State-of-art, challenges and future perspectives

Abstract: With quantum computing, we are witnessing an exciting and very promising merging of three of the deepest and most successful scientific and technological developments of modern era: quantum physics, computer science, and nanotechnology Quantum computers have the potential to perform certain calculations billions of times faster than any silicon-based computer A functional quantum computer will be invaluable in factoring large numbers, and therefore extremely useful for decoding and encoding secret information In this paper we have discussed contemporary cryptographic systems and their strengths and drawbacks Two of the most common quantum key distribution protocols have been explained This is followed by a note on the experimental realizations of quantum key distribution and the associated technological challenges A few novel extensions of this concept in the future have also been dealt with This paper aims at familiarizing the reader with the field of quantum cryptography and gives an insight about the latest developments

Quantum bit controller and observer circuits in SOS-CMOS technology for gigahertz low-temperature operation

Abstract: Quantum bit (qubit) control and readout requires controller-qubit-observer systems for rapid control signal generation and injection to the qubit gates, and observation of their final state projections. Conventionally, for solid-state qubits, this is achieved by generating the control signal at 300 K and transmitting it along very long coaxial cables that span from 300 K to sub-K (typically les 500 mK), then reading out the response from charge proximity sensors such as single-electron transistors along similar lengths of cable. Our approach is to fabricate the classical controller and observer circuits using a commercial foundry processed silicon-on-sapphire (SOS) RFCMOS technology for operation at low temperatures (either at 4.2 K, 1 K, or sub-K). We have demonstrated SOS-CMOS NFET and PFET device operation at 4.2 K, and sub-K that showed deviations from their 300 K characteristics, but with further experiments these were shown to have minimal effects on control circuit function. Using these results, we have fabricated and demonstrated a low-power proof-of-concept SOS-CMOS controller circuit (monostable 100 ps voltage-pulse generator) that can operate at sub-K temperatures in a dilution refrigerator. We briefly discuss experimental and conceptual schemes with which we can develop qubit control systems for cryogenic and lower temperatures. These low temperature experiments also demonstrate that commercial SOS RF-CMOS technology can be feasible for other low temperature and low power applications.

Reliability of bi-stable single domain nano magnets for Cellular Automata

Abstract: Quantum cellular automata, also known as QCA, has been touted as a pragmatic use of quantum phenomena which currently are detrimental in nano-transistor technology. Recently, QCA technologies has expanded into magnetism, an area referred to as magnetic QCA, by exploiting the magnetic coupling interaction between neighboring cells (nano-magnets). The interactions of orderly fabricated nano-magnets and the viability of nano-magnetic structures as logical building blocks has yet to be explored in great detail. We have fabricated nano-scale magnetic QCA cells and currently the scope entails determining how factors such as material, size, placement, and surface roughness affect the magnetic properties and coupling interactions between the nano- magnetic QCA cells.

Investigating the motion of molecular machines on surfaces by STM: The nanocar and beyond

Abstract: To build up true molecular machines and understand the mechanics of nanoscale motion and manipulation in molecular system, we have created and investigated a family of molecules based around the concept of the nanocar, which has the rolling wheels made of spherical fullerene or carborane molecules. Assisted by scanning tunneling microscopy (STM), we have successfully characterized and manipulated these molecules. In addition, we have observed the behavior of these systems when thermal energy is applied. These initial studies open a new realm of nano-sized mechanical, chemical, and electrical devices.

Effect of single grain boundary position on surrounding-gate polysilicon thin film transistors

Abstract: In this paper, single-grain-boundary-position-induced electrical characteristic variations in 300 nm surrounding-gate (i.e, gate-all-around, GAA) polysilicon thin film transistors (TFTs) are numerically investigated. For a 2T1C active-matrix circuit, a three-dimensional device-circuit coupled mixed-mode simulation shows that the switching speed of GAA TFT can be improved by nine times, compared with the result of the circuit using single-gate (SG) polysilicon TFTs. The position of single grain boundary near the drain side has an ill effect on device performance, but the influence can be suppressed in the GAA polysilicon TFTs. We found that under the same threshold voltage, the variation of threshold voltage can be reduced from 15 % to 5 %, with varying of gate structures of the GAA polysilicon TFT.

Needleless electroSpinning of multiple nanofibers

Abstract: To satisfy the increasing applications of the electrospun nanofibers, a novel method for the high throughput nanofibers electrospinning which is called "Needleless ElectroSpinning (NES)" is presented in the article. Instead of using the conventional needle, ElectroHydroDynamics (EHD) instabilities mechanism on the electrified liquid film free surface forms the foundation of the NES process, in which, we use a metal cylindrical rotator with smooth or tipped surface as the spinneret electrode, and the production rate of nanofibers can be controlled by adjusting the length and diameter of cylindrical rotator. The main factor such as solution concentration, the diameter of cylindrical rotator, the distance between the rotator and the grounded collector and so on are investigated in our experiment. Results show that solid nanofibers with diameter of 100 nm-800 nm can be electrospun onto metal substrate with electrode-to-substrate distance of 10-20 cm under bias of 40-70 kV. Compared with the conventional electrospinning method, the yield is expected to be increased by more than 125 times.

Clock-free nanowire crossbar architecture based on Null Convention Logic (NCL)

Abstract: There have been numerous nanowire crossbar architectures proposed till date, although all of them are envisioned to be synchronous (i.e., clocked). The clock is an important part in a circuit and it needs to be connected to all the components to synchronize their operation. Considering non-deterministic nature of nanoscale integration, realizing them on a nano wire crossbar system would be quite cumbersome. Unlike the conventional clocked counterparts, a new clock-free crossbar architecture is proposed to resolve the issues with clocked counterparts in this paper, where the use of clock is eliminated from the architecture. This has been done by implementing delay-insensitive logic encoding technique called Null Convention Logic (NCL). A delay-insensitive full adder has been implemented on the proposed architecture to demonstrate the feasibility in this paper.

A ZEP520-LOR bilayer resist lift-off process by e-beam lithography for nanometer pattern transfer

Abstract: In this work, a bilayer resist system with ZEP520 as the top layer and lift-off resist (LOR) as the bottom layer for lift-off process was investigated for the first time. The formation of undercut was studied as a critical step which makes lift-off process much more feasible in bilayer resist process. Using different dissolution rates of LOR layer, the length of undercut can be well controlled, providing reliable process. The top layer of ZEP520 is more efficient than other resists (PMMA etc.) for e-beam lithography, due to its high resolution and high sensitivity. Here, a set of process parameters have been optimized to fabricate Cr metal lines with a width of less than 70 nm. This bilayer lift-off resist system can be widely used in nano-fabrication for various nano-scale structures and devices.

Surface energy induced patterning of polymer nanostructures for cancer diagnosis and therapy

Abstract: We have developed a new simple method to pattern discrete polymer micro and nanostructures. A Si template is patterned by lithography and selective surface treatment to have spatially different surface energies that induce microfluidic self-patterning of a spincoated polymer layer. Biocompatible diblock co-polymer and SU8 are patterned using this method to form monodisperse and shape specific microstructures. After patterning, these particles are lifted off the template surface into aqueous solution. The template is then cleaned and re-used. These freestanding polymer particles with uniform and precise spherical morphology can be used as carriers for drug and imaging agents for biomedical applications.

Packaging carbon nanotube based infrared detector

Abstract: We present a fabrication and packaging method of carbon nanotube (CNT) based infrared (IR) sensor chip using parylene C layer. CNT was found to be sensitive under near IR radiation and it could be used as IR sensing element. Parylene C thin film was used as a conformal pin hole free insulating layer and oxygen barrier for protecting CNTs during the detection. The IR transmission properties of parylene C layer and the influence on the response of the CNT sensor were studied. Our experimental results showed that the CNT sensor without parylene C protection exhibited current change when it was exposed to the IR laser. The sensing current percentage changes decreased when the parylene C thin film substrate was placed between the CNT sensor and IR laser source. It implied the IR absorption behavior of parylene C thin film. We also found that the IR absorption level is proportional to the thickness of the parylene C layer. The parylene C packaged CNT sensor was fabricated and tested under near IR radiation. Preliminary results indicated that the CNT IR detector coated with parylene C was capable of sensing IR radiation and exhibited repeatable response. Moreover, the IV characteristic of the sensor chip was measured when it was surrounded by dry ice for long time to investigate its long term stability under moisture environment. Therefore, the packaging process can become possible to fabricate a CNT based IR sensor array which possesses more stable and reliable performance.

Electronic and transport properties of graphene nanoribbons

Abstract: We present the electronic structures and transport properties of hydrogen-saturated graphene ribbons and its dependence on its termination edge, ribbon width, and impurity. The band structures, transmission spectrum, and current-voltage (I-V) characteristics of graphene ribbons have been calculated by using first-principles electronic structure methods and non-equilibrium Green's functions technique. Our calculated results show that the graphene ribbons with zigzag shaped edges exhibit nonlinear behavior of I-V characteristics due to the overlapping of pi* and pi bands around Fermi level. As the width of zigzag chain of graphene ribbons increases, the overlapping of pi* and pi bands is enhanced and the voltage range for linear I-V response becomes narrower. The graphene ribbons with armchair shaped edges exhibit semiconducting properties and the band gap decreases with increasing ribbon width. The doping of B or N in graphene ribbons with armchair shaped edges slightly increases the current at lower bias voltage.

The design of the sub-wavelength wire-grid polarizer

Abstract: According to the request of the sensitive wave band of 0.38 mum-0.52 mum of the bionic micro-nano navigation sensor, the paper designed a wire-grid polarizer which can be effectively used in the region of blue-violet light spectrum based on rigorous coupled-wave theory. The difference between the designed wire-grid polarizer and the conventional wire-grid polarizer is that the former adds the magnesium fluoride film between the substrate and the wire-grid, and etches a portion of the magnesium fluoride film. Numerical results and theoretical analysis presented that the designed wire-grid polarizer is a broadband., high TM polarization transmission efficiencies and high extinction ratios polarizer. The paper also discussed the performance of the designed grating affected by oxidation of aluminum. The effects of the oxide layer are that the TM transmission efficiencies increase slightly, whereas the extinction ratios decrease rapidly. The paper had the conclusion that the effects of the oxide layer can be almost attributed to the reduction in duty cycle and wire thickness it causes. Finally, the paper discussed the relationship between the number of orders retained and the convergence of the calculation numerical. Numerical results and theoretical analysis presented that the rate of convergence of the TM diffraction efficiency is much slower than the rate of convergence of the TE diffraction efficiency. The paper concluded that the reason of the phenomenon is that the TM polarization has multiple vector components which lead to large evanescent field.

Design of a high sensitivity capacitive force sensor

Abstract: This paper presents the design and development of a MEMS based, capacitive sensor for micro-force measurement. The sensor has an overall dimension of 3600 mum times 1000 mum times 10 mum and was fabricated using the Micragem fabrication process. A displacement reduction mechanism is incorporated in this sensor design to increase the sensitivity of the sensor. Analysis from Finite Element software, COMSOL, confirms that a 10:1 displacement reduction ratio is achievable with this mechanism. Simulation results show that the sensor is capable of measuring a maximum force input of 11 milli-Newton, resulting from a 20-mum displacement on the sensing structure. A 6-DOF manipulator and an evaluation board were used to experimentally verify the performance the sensor. Experimental results show that a capacitance change of approximately 175 to 200 fF can be observed from a 20-mum displacement.

System modeling of an AFM System in Z-axis

Abstract: Motivated by increasing the scanning performance of the atomic force microscope (AFM), many efforts have been made to analyze the system behavior of an AFM system, mainly in Z-axis, and then to develop more advanced controllers. However, most of the previously derived models involve complex physical or mathematical analysis, and many parameters need to be identified for actual application. In this paper, an empirical model is obtained for the Z-axis dynamics of an AFM system by utilizing experimental data. Specifically, the model consists of a dynamical component and multiple static gains. As introduced in the paper, the N4SID algorithm is first employed to derive the dynamical part based on input-output data. Then the static gains of the piezo-actuator are calibrated experimentally. It can be seen from the experimental data that the main source of time delay in Z-axis is the finite retraction/protraction velocity of the piezo-actuator.