In following paper we propose method of energetic description for active microcantilevers. Microelectromechanical devices (MEMS), to which the microcantilevers belong, are becoming part of energy generation and transformation systems. Therefore efficiency of said devices becomes significant parameter. In our approach we described the method to estimate the efficiency based on the measured parameters of a cantilever and it’s effective movement under actuation. We have conducted measurements an calculations for series of cantilevers actuated electrothermally and electromagnetically. Acquired results are in line with predicted properties of examined MEMS’. Method is suited for description of microcantilevers, assessment of utility and comparison in case of common application. [2022-0043]

Contemporary prosthetic materials are characterized by highly specific preparation for a given application. This means that at the stage of their creation, not only their function is taken into account, but also the long-term behavior of this material during use. In the case of telescopic crowns, an important factor not yet appearing in the research is the aspect of adhesion force and its dependence on the type of biomaterial, but also the properties of human saliva. The use of artificial saliva, which creates a lubricating layer, reduces the wear on the surface of the telescopic crowns by reducing friction. The impact of artificial saliva on the formation of chemical bonds between prosthetic elements, thus contributing to the so-called retention force has not yet been studied. In this work, two types of measurements of gold telescopic crown materials in the aspect of the adhesion process are presented. Obtained results allowed to fully characterize this phenomenon. We modeled the load force between the microcircuit and the surface under study to suit the conditions between the primary and secondary crowns in the patient's mouth.

In this paper, we present metrology and control methods and techniques for electromagnetically actuated microcantilevers.The electromagnetically actuated cantilevers belong to the micro electro mechanical systems (MEMS), which can be used in high resolution force and mass change investigations.In the described experiments, silicon cantilevers with an integrated Lorentz current loop were investigated.The electromagnetically actuated cantilevers were characterized using a modified optical beam deflection (OBD) system, whose architecture was optimized in order to increase its resolution.The sensitivity of the OBD system was calibrated using a reference cantilever, whose spring constant was determined through thermomechanical noise analysis registered interferometrically.The optimized and calibrated OBD system was used to observe the resonance and bidirectional static deflection of the electromagnetically deflected cantilevers.After theoretical analysis and further experiments, it was possible to obtain setup sensitivity equal to 5.28 mV/nm.

The rational design of novel self-assembled nanomaterials based on peptides remains a great challenge in modern chemistry. A hierarchical approach for the construction of nanofibrils based on α,β-peptide foldamers is proposed. The incorporation of a helix-promoting trans-(1S,2S)-2-aminocyclopentanecarboxylic acid residue in the outer positions of the model coiled-coil peptide led to its increased conformational stability, which was established consistently by the results of CD, NMR and FT-IR spectroscopy. The designed oligomerization state in the solution of the studied peptides was confirmed using analytical ultracentrifugation. Moreover, the cyclopentane side chain allowed additional interactions between coiled-coil-like structures to direct the self-assembly process towards the formation of well-defined nanofibrils, as observed using AFM and TEM techniques.

Atomic force microscopy enables three-dimensional high-resolution imaging of surfaces with nanoscale features. In order to obtain the quantitative information about surface geometry, the atomic force microscope’s scanning system must be calibrated. This is usually done by using calibration samples of known and/or defined shape based on either lithographic or crystal structures. In this work we report on a microelectromechanical device, referred to as a displacement generator, whose vertical deflection is controlled electronically. The designed, fabricated and applied device is formed out of a silicon nitride doubly clamped lever, referred to as a microbridge, with a deposited pair of platinum strips. When the MEMS displacement generator is immersed in a magnetic field and when it is electrically biased, the associated Lorentz force induces a structural displacement. In the presented design, the silicon nitride microbridges were fabricated on a (110) silicon wafer in a Wheatstone bridge configuration. A second reference cantilever was mechanically supported by the silicon substrate. In this way, a highly symmetrical structure was fabricated, making it possible to control precisely deflection in Z direction with sub-nanometre precision. The cantilever’s high resonance frequency, of ca. 500 kHz, makes the constructed device insensitive to external vibration sources which are typically at much lower frequencies. As the stage function can be described using the simple harmonic oscillator model, it is clear that the system can operate with sub-nanometre resolution, which, for the purpose of microscope calibration, is extremely beneficial. By placing of the atomic force microscope tip on the actuated reference device it is possible to determine the response of the system over a wide frequency bandwidth. In this work we will describe the fabrication process of the MEMS displacement generator, interferometric and traceable investigations of thermomechanical and electromagnetic actuation schemes. Moreover, we will present the results of the calibration of an atomic force microscope operating in contact and intermittent contact modes.

Scanning electron microscopy (SEM) is a perfect technique for micro-/nano-object imaging [1] and movement measurement [2, 3] both in high and environmental vacuum conditions and at various temperatures ranging from elevated to low temperatures. In our view, the magnetic field expanding from the pole-piece makes it possible to characterize the behaviour of electromagnetic micro- and nano electromechanical systems (MEMS/NEMS) in which the deflection of the movable part is controlled by the electromagnetic force. What must be determined, however, is the magnetic field expanding from the e-beam column, which is a function of many factors, like working distance (WD), magnification and position of the device in relation to the e-beam column. There are only a few experimental methods for determination of the magnetic field in a scanning electron microscope. In this paper we present a method of the magnetic field determination under the scanning electron column by application of a silicon cantilever magnetometer. The micro-cantilever magnetometer is a silicon micro-fabricated MEMS electromagnetic device integrating a current loop of lithographically defined dimensions. Its stiffness can be calibrated with a precision of 5% by the method described by Majstrzyk et al. [4]. The deflection of the magnetometer cantilever is measured with a scanning electron microscope and thus, through knowing the bias current, it is possible to determine the magnetic field generated by the e-beam column in a defined position and at a defined magnification.

Micromechanical cantilevers are attractive devices for force measurements. We report the results obtained for SMMM (Soft MetMoIMEMS) silicon cantilever fabricated on silicon on insulator (SOI) substrate with piezoresistive deflection readout with the stiffness much lower than the typical piezoresistive silicon cantilever. The cantilever mechanical properties were characterised with laser vibrometer using the thermal noise technique (resonant frequency f(res) = 5474.2 Hz, quality factor Q = 19.4 and stiffness k = 0.042 Nm(-1)). The piezoresistive detection sensitivity was evaluated by measuring externally induced mechanical vibrations optically with laser vibrometer and electrically using current-to-voltage converter and lock-in amplifier simultaneously. We obtained deflection sensitivity DS = 11 Vm(-1) and force sensitivity FS = 263 VN-1 assuming typical bias voltage of 2 V. Such silicon cantilever may be successfully used in AFM investigation of fragile structures. (C) 2019 Elsevier B.V. All rights reserved.

Scanning probe microscopy (SPM) since its invention in the 80's became very popular in examination of many different sample parameters, both in university and industry.This was the effect of bringing this technology closer to the operator.Although the ease of use opened a possibility for measurements without high labour requirement, a quantitative analysis is still a limitation in Scanning Probe Microscopes available on the market.Based on experience of Nano-metrology Group, SPM still can be considered as a tool for quantitative examination of thermal, electrical and mechanical surface parameters.In this work we present an ARMScope platform as a versatile SPM controller that is proved to be useful in a variety of applications: from atomic-resolution STM (Scanning Tunnelling Microscopy) to Multi-resonance KPFM (Kelvin Probe force microscopy) to commercial SEMs (Scanning electron microscopes).

Atomic force microscopy (AFM) belongs to the high resolution and high sensitivity surface imaging technologies. In this method force interactions between the tip and the surface are observed to characterize sample properties. In the so-called contact AFM (C AFM) mode the tip is brought into continuous contact with the sample. Significant progress in the AFM technology can be obtained, when the so-called active cantilever technology is implemented in the surface measurements. The built-in deflection actuator enables very precise excitation of the cantilever. Moreover, as the mass of the beam is very small the static beam displacement can be controlled in the wide frequency range. In the experiments, which we describe in this article, we applied the so called active electromagnetic cantilevers. They integrate a conductive loop which, when immersed in the magnetic field and biased with electric current, acts as an electromagnetic deflection actuator. The induced and precisely estimated Lorentz force, which is a function of bias current, cantilever geometry and magnetic field makes the cantilever deflect. Moreover, the probe stiffness can be calibrated with lower uncertainty as in the case of standard thermomechanical analysis. NZ AFM technology required application of a novel control algorithm, called PredPID, in which the cantilever bending caused by a proportional-integral-derivative (PID) block maintaining the constant load force was predicted.

PURPOSEThe surface roughness of the dental restorations is significant to the denture plaque adhesion.METHODSIn this work, we present the complex analysis of the electropolished CoCrW alloy remanium® star (Dentaurum, Germany) samples with laserengraved fiducial marks performed using complementary set of micro- and nanoscopic techniques: optical profilometry (OP), atomic force microscopy (AFM), scanning electron microscopy (SEM) and focused ion beam (FIB) milling.RESULTSBoth mean and RMS roughness of the samples were reduced by electopolishing process, however, the results obtained using OP and AFM exhibited some discrepancies. This was caused by the relatively high local protruding defects developed on the processed surface. The cross-sections of the protrusions were made to analyze the cause of their formation as the EDS elemental content maps revealed that their composition was uniform. We also analyzed the local roughness in the smaller areas free from the defects.CONCLUSIONSIn that case, both OP and AFM techniques delivered the same results. Analysis of results showed that various methods used for the surface roughness evaluation have to be used simultaneously to obtain complete and true analysis of the technological CoCrW samples.

In this paper we present the numerical and experimental results of a design optimization of electromagnetic cantilevers. In particular, a cost-effective technique of evolutionary computing enabling the simultaneous minimization of multiple criteria is applied. A set of optimal solutions are subsequently fabricated and measured. The designed cantilevers are fabricated in arrays, which makes the comparison and measurements of the sensor properties reliable. The microfabrication process, based on the silicon on insulator (SOI) technology, is proposed in order to minimize parasitic phenomena and enable efficient electromagnetic actuation. Measurements on the fabricated prototypes assessed the proposed methodological approach.

In this work we present how to describe mechanical impedance of a photon force (PF) MEMS sensor dedicated to structures’ optomechanical studies. An actuating force (photon force) is caused by the reflection and absorption of the electromagnetic radiation beam due to the radiation pressure effect. Specially designed very soft (low k-constant, ca 10–150 mN/m) cantilevers are presented. The structures integrate a Lorentz loop, which enables electromagnetic actuation. The construction with two mirrors is proposed so that parasitic thermal actuation can be neglected. The MEMS displacement is measured with the use of a laser vibrometer. The mechanical impedance model is presented using which the stiffness is calculated. As validation measurements: thermal noise and known mass adding methods are used.

Radiation pressure - RP phenomenon has drawn much interest since the beginning of the 20th century. There are many technologies linked with it and worth mentioning: cavity optomechanics with optical cooling and small forces amplification, single atom trapping, cantilevers spring constant calibration or high-power laser measurement. Nevertheless, the quantitative measurement of the RP is always influenced by many parasitic effects e.g. photothermal effects, which can appear while the beam is absorbed. The goal of the investigations presented in this paper was to design and manufacture a MEMS tool, the so-called RP cantilever, for the reliable interactions studies (i.e. due to radiation pressure) where the photothermal effect is highly reduced. Besides design and manufacturing process we present a set of experiments showing the properties of the proposed technology and its application possibilities.

In this work we propose a method for on-cantilever force control for application in force distance (F-z) spectroscopy for intermolecular interaction sensing. In this method we perform the F-z measurements with cantilevers integrating functionalized spheres attached to them. The F-z curve is obtained by controlling the Lorentz force acting at the cantilever free end. The intermolecular interaction forces are measured by measuring the force necessary to retract the cantilever from the surface. The required force is generated by the current passing through the cantilever. In this scenario we monitor the bending of cantilevers using optical beam deflection (OBD) method. Moreover, as deflection of the cantilever was electromagnetically controlled it was possible to calibrate the OBD response as well.

Most commonly instruments utilizing cantilever-based sensors are equipped with optical beam deflection (OBD) detectors. The devices utilizing OBD setup are of simple construction, however it is quite difficult to calibrate their response. This is especially important for the instruments applied in biochemical investigation, where all the interesting phenomena happen within a fluidic cell. This limit comes from the fact than most common approach to calibrate an OBD system is to apply know deflection from a piezoelectric scanner and calibrate the OBD detector response. Here we present an electromagnetic cantilever reference which has the ability to overcome these limits. We show how its deflection can be precisely calibrated and then it can act as a transfer deflection standard. We do this by providing a calibration under known electromagnetic field and we analyze forces with a FEM model. We show that the proposed electromagnetic cantilever reference can be applied in a system with unknown response and accurately calibrate its response. (C) 2018 Elsevier B.V. All rights reserved.

The self-actuating and self-sensing cantilevers make it possible to perform precise non-contact atomic force microscopy (AFM) surface investigations. The measurement and control precision in the bandwidth of up to 2 MHz is ensured by integration of the most important microscope components: the tip deflection actuator and the tip deflection detector with the spring beam. In this way the vast majority of the parasitic disturbances like resonances of a bulk piezoactuator used for the cantilever excitation are eliminated. In this paper we describe thermomechanical and electromagnetic technologies for the actuation of the cantilever vibration whose oscillation is detected using the piezoresistive deflection sensor. We present how to control the cantilever mechanics using both actuation methods. We discuss the differences in power consumption when the cantilever is actuated and what are the surface scanning features of both technologies. We show that an atomic force microscope is capable of retaining its imaging speed and resolution when its cantilever is actuated in the thermomechanical and electromagnetic way. The obtained results illustrate that the selection of the proper actuation method extends applicability of the proposed AFM technologies. (C) 2018 Elsevier B.V. All rights reserved.

Microcantilever-based sensors are very promising devices for biochemical applications. They are usually operated in two modes. In the first one, a microcantilever static bending induced by the surface stress is observed. In the second mode, resonant frequency shift caused by mass loading is measured. The second mode requires an external force to excite cantilever vibrations. There is a possibility to use a stochastic excitation signal to estimate frequency shift as well as other interesting mechanical properties, such as effective spring constant or damping. Cantilever thermal self-vibrations or artificially generated white noise are very convenient examples of such a stochastic excitation signal.In the paper a real-time stochastic response analysis (RTSA) technique is presented. It is based on autoregressive moving average (ARMA) process modeling. Estimated model parameters are used for calculation of the eigenfrequency, quality factor and effective spring constant of a given vibration mode. The description of the entire procedure is presented, along with the results of simulations. The results confirm validity of the proposed ARMA model and show expected estimation errors for an illustrative set of cantilevers.The proposed algorithm is also applied to monitor the quality factor and resonant frequency of an electromagnetically-actuated microcantilever. The stochastic signal used to excite the cantilever is generated by a very simple white noise generator. The RTSA enables simultaneous monitoring of the cantilever resonant frequency and quality factor.The proposed solution is an interesting option in applications, in which simplicity and cost of the measurement system are key issues. (C) 2016 Elsevier Ltd. All rights reserved.

In this paper we present the design, technology and application of Si/Si3N4 micro calibration stage equipped with Pt microheaters. This 500nm thick MEMS structure with 4 independently controlled microheaters allows for precise control temperature dissipation and contact between surface and tip of cantilever. Localization on thin, low thermally conductive membrane minimizes the heat transfer to the bulk silicon. In order to increase mechanical stability of the structure, the membrane is supported by the tip. Structure stiffness is increased which allows for characterization of relatively stiff (30–70Nm−1) piezoresistive scanning thermal microscopy probes. The small size and spatial arrangement of independent heaters allows for the controlled heat flow in the membrane and measurements of the temperature distribution.

In this paper the authors compare methods used for piezoresistive microcantilevers actuation for the atomic force microscopy (AFM) imaging in the dynamic shear force mode. The piezoresistive detection is an attractive technique comparing the optical beam detection of deflection. The principal advantage is that no external alignment of optical source and detector are needed. When the microcantilever is deflected, the stress is transferred into a change of resistivity of piezoresistors. The integration of piezoresistive read-out provides a promising solution in realizing a compact non-contact AFM. Resolution of piezoresistive read-out is limited by three main noise sources: Johnson, 1/f and thermomechanical noise. In the dynamic shear force mode measurement the method used for cantilever actuation will also affect the recorded noise in the piezoresistive detection circuit. This is the result of a crosstalk between an aluminium path (current loop used for actuation) and piezoresistors located near the base of the beam. In this paper authors described an elaborated in ITE (Institute of Electron Technology) technology of fabrication cantilevers with piezoresistive detection of deflection and compared efficiency of two methods used for cantilever actuation.

Cantilever based sensor system are a well-established sensor family exploited in several every-day life applications as well as in high-end research areas. The very high sensitivity of such systems and the possibility to design and functionalize the cantilevers to create purpose built and highly selective sensors have increased the interest of the scientific community and the industry in further exploiting this promising sensors type. Optical deflection detection systems for cantilever sensors provide a reliable, flexible method for reading information from cantilevers with the highest sensitivity. However the need of using multi-cantilever arrays in several fields of application such as medicine, biology or safety related areas, make the optical method less suitable due to its structural complexity. Working in the frame of a the Joint Undertaking project Lab4MEMS II our group proposes a novel and innovative approach to solve this issue, by integrating a Micro-Opto-Electro-Mechanical-System (MOEMS) with dedicated optics, electronics and software with a MOEMS micro-mirror, ultimately developed in the frame of Lab4MEMSII. In this way we are able to present a closely packed, lightweight solution combining the advantages of standard optical read-out systems with the possibility of recording multiple read-outs from large cantilever arrays quasi simultaneously.