Development of microcantilever sensors for cell studies

Micro- and nano- electromechanical devices such as microcantilevers have paved the way for a large variety of new possibilities, such as the rapid diagnosis of diseases and a high throughput platform for drug discovery. Conventional cell assay methods rely on the addition of reagents, disrupting the measurement, therefore providing only the endpoint data of the cell growth experiment. In addition, these methods are typically slow to provide results and time and cost consuming. Therefore, microcantilever sensors are a great platform to conduct cell culturing experiments for cell culture, viability, proliferation, and cytotoxicity monitoring, providing advantages such as being able to monitor cell kinetics in real time without requiring external reagents, in addition to being low cost and fast, which conventional cell assay methods are unable to provide. This work aims to develop and test different types of microcantilever biosensors for the detection and monitoring of cell proliferation. This approach will overcome many of the current challenges facing microcantilever biosensors, including but not limited to achieving characteristics such as being low cost, rapid, easy to use, highly sensitive, label-free, multiplexed arrays, etc. Microcantilever sensor platforms utilizing both a single and scanning optical beam detection methods were developed and incorporated aspects such as temperature control, calibration, and readout schemes. Arrays of up to 16 or 32 microcantilever sensors can be simultaneously measured with integrated microfluidic channels. The effectiveness of these cantilever platforms are demonstrated through multiple studies, including examples of growth induced bending of polyimide cantilevers for simple real-time yeast cell measurements and a microcantilever array for rapid, sensitive, and real-time measurement of nanomaterial toxicity on the C3A human liver cell line. In addition, other techniques for microcantilever arrays and microfluidics will be presented along with demonstrations for the ability for stem cell growth monitoring and pathogen detection

Microcantilever biosensors

The cross-sensitivity of microcantilever sensors presents a major obstacle in the development of a commercially viable microcantilever biosensor for point of care testing. This thesis concerns electrothermally actuated bi-material microcantilevers with piezoresistive read out, developed for use as a blood coagulometer. Thermal properties of the sensor environment including the heat capacity and thermal conductivity affect the ‘thermal profile’ onto which the higher frequency mechanical signal is superimposed. In addition, polymer microcantilevers are known to have cross-sensitivity to relative humidity due to moisture absorption in the beam. However it is not known whether any of these cross sensitivities have a significant impact on performance of the sensor during pulsed mode operation or following immersion into liquid. When analysing patient blood samples, any change in signal that is not caused by the change in blood viscosity during clotting could lead to a false result and consequently an incorrect dose of anticoagulants may be taken by the patient. In order to address these issues three aspects of the operation of polymer bi-material strip cantilevers has been researched and investigated: relative humidity; viscosity/density, and thermal conductivity of a liquid environment. The relative humidity was not found to affect the resonant frequency of a microcantilever operated in air, or to affect the ability of the cantilever to measure clot times. However, a decrease in deflection with increasing relative humidity of the SmartStrip microcantilever beams is observed at 1.1 ± 0.4 μm per 1% RH, and is constant with temperature over the range 10 – 37 °C, which is an issue that should be considered in quality control. In this study, the SmartStrip was shown to have viscosity sensitivity of 2 cP within the range 0.7 – 15.2 cP, and it was also shown that the influence of inertial effects is negligible in comparison to the viscosity. To investigate cross-sensitivity to the thermal properties of the environment, the first demonstration of a cantilever designed specifically to observe the thermal background is presented. Characterisation experiments showed that the piezoresistive component of the signal was minimised to -0.8% ± 0.2% of the total signal by repositioning the read out tracks onto the neutral axis of the beam. Characterisations of the signal in a range of silicone oils with different thermal conductivities gave a resolution to thermal conductivity of 0.3 Wm-1K-1 and resulted in a suggestion for design improvements in the sensor: the time taken for the thermal background signal to reach a maximum can be increased by increasing the distance between the heater and sensor, thus lessening the impact of the thermal crosstalk within the cantilever beam. A preliminary investigation into thermal properties of clotting blood plasma showed that the sensor can distinguish the change between fresh and clotted plasma

Integrated microcantilever fluid sensor as a blood coagulometer

The work presented concerns the improvement in mechanical to thermal signal of a microcantilever fluid probe for monitoring patient prothrombin time (PT) and international normalized ratio (INR) based on the physical measurement of the clotting cascade. The current device overcomes hydrodynamic damping limitations by providing an internal thermal actuation force and is realised as a disposable sensor using an integrated piezoresistive deflection measurement. Unfortunately, the piezoresistor is sensitive to thermal changes and in the current design the signal is saturated by the thermal actuation. Overcoming this problem is critical for demonstrating a blood coagulometer and in the wider field as a microsensor capable of simultaneously monitoring rheological and thermal measurements of micro-litre samples. Thermal, electrical, and mechanical testing of a new design indicates a significant reduction in the thermal crosstalk and has led to a breakthrough in distinguishing the mechanical signal when operated in moderately viscous fluids (2-3 cP). A clinical evaluation has been conducted at The Royal London Hospital to measure the accuracy and precision of the improved microcantilever fluid probe. The correlation against the standard laboratory analyser INR, from a wide range of patient clotting times(INR 0.9-6.08) is equal to 0.987 (n=87) and precision of the device measured as the percentage coefficient of variation, excluding patient samples tested < 3 times, is equal to 4.00% (n=64). The accuracy and precision is comparable to that of currently available point-of-care PT/INR devices. The response of the fluid probe in glycerol solutions indicates the potential for simultaneous measurement of rheological and thermal properties though further work is required to establish the accuracy and range of the device as a MEMS based viscometer

Design and development of microcantilever as a platform for moisture sensing

Ultra-sensitive and selective moisture sensors are needed in various industries for processing control or environmental monitoring. As an outstanding sensor platform, microcantilevers have potential application in moisture detection due to their advantages, such as low-level moisture detection limits, high accuracy, quick response time, high reproducibility, good recovery rate and low in cost. Our research results will lead to the first of its kind for the commercialization of a microcantilever-based moisture sensor used for industrial and household applications. The novelty of the present work is the development of SiO2 and Si cantilevers, which were fabricated using developed processes and modified with Al2O3, for detecting moisture as low as ppm level. To increase the deflection of the microcantilever under surface stress induced by specific reactions, a new SiO2 microcantilever, which consists of two SiO2 cantilever beams as the sensing and reference elements, two connecting wings and three guard arms, has been developed which features a much lower Young\u27s modulus than conventional Si or SiNx microcantilevers. For comparing SiO2 cantilever with Si cantilevers, a model of the cantilever sensor is reported by using both analysis and simulation, resulting in good agreement with the experimental data. The results demonstrate that the SiO2 cantilever can achieve a much higher sensitivity than the Si cantilever due to its lower Young\u27s modulus. In order to fabricate this device, a new fabrication process using isotropic combined with anisotropic dry etching to release the SiO2 microcantilever beam by Inductively Coupled Plasma (ICP) was developed and investigated. This new process not only obtains a high etch rate at 9.1 μm per minute, but also provides good etch profile controllability, and a flexibility of device design. Attributed to its high sensitivity, Al2O3 coated SiO2 microcantilevers demonstrated the capability of detecting moisture concentration levels down to 30 ppm using optical detection methods. It can be seen that the SiO2microcantilevers, with appropriate sensing material, can be utilized as ultra sensitive moisture sensors and are potentially able to detect the moisture concentration level as low as 1 to 10 ppm. Although optical readout systems are most extensively used for measurement of cantilever deflections in labs, they have some disadvantages, such as its alignment system is expensive and involves great precision. Piezoresistive, capacitive, MOSFET-embedded and frequency readout methods, which are all fit for commercial application, have been investigated both in simulation and experiment. It is found that the Al2O3 modified microcantilever operating in frequency mode is able to meet the requirements of detecting low moisture levels. To make this device compatible with IC technology, the piezoelectric microcantilever is chosen as the platform for moisture sensing. A piezoelectric microcantilever vibrates at its resonant frequency upon applying an appropriate AC voltage and provides an electrical signal at the output via piezoelectric coupling, which can be fed back through the phase shift loop to determine the change in resonant frequency caused by any change in mass. In order to fabricate the piezoelectric microcantilever, the sputtering parameters for ZnO were reported and investigated. The piezoelectric microcantilevers, which consists of bottom electrode, ZnO piezoelectric layer, and two separate top electrodes as sensing and actuation elements, were designed and fabricated using a standard lithography process. Its resonant frequency shift is measured at 1.25 Hz/ppm, based on an optical detection method. Although both SiO 2 and Si piezoelectric cantilevers were fabricated successfully, the latter are more likely to be used in dynamic mode because of the higher fragility of SiO2. The developed cantilever sensor platform operating in dynamic mode, which can be integrated with on-chip electronic circuitry, is able to provide ultra-sensitive detection, not only for moisture sensing, but also for chemical and biological sensing with appropriate surface modification

Novel miniaturised and highly versatile biomechatronic platforms for the characterisation of melanoma cancer cells

There has been an increasing demand to acquire highly sensitive devices that are able to detect and characterize cancer at a single cell level. Despite the moderate progress in this field, the majority of approaches failed to reach cell characterization with optimal sensitivity and specificity. Accordingly, in this study highly sensitive, miniaturized-biomechatronic platforms have been modeled, designed, optimized, microfabricated, and characterized, which can be used to detect and differentiate various stages of melanoma cancer cells. The melanoma cell has been chosen as a legitimate cancer model, where electrophysiological and analytical expression of cell-membrane potential have been derived, and cellular contractile force has been obtained through a correlation with micromechanical deflections of a miniaturized cantilever beam. The main objectives of this study are in fourfold: (1) to quantify cell-membrane potential, (2) correlate cellular biophysics to respective contractile force of a cell in association with various stages of the melanoma disease, (3) examine the morphology of each stage of melanoma, and (4) arrive at a relation that would interrelate stage of the disease, cellular contractile force, and cellular electrophysiology based on conducted in vitro experimental findings. Various well-characterized melanoma cancer cell lines, with varying degrees of genetic complexities have been utilized. In this study, two-miniaturized-versatile-biomechatronic platforms have been developed to extract the electrophysiology of cells, and cellular mechanics (mechanobiology). The former platform consists of a microfluidic module, and stimulating and recording array of electrodes patterned on a glass substrate, forming multi-electrode arrays (MEAs), whereas the latter system consists of a microcantilever-based biosensor with an embedded Wheatstone bridge, and a microfluidic module. Furthermore, in support of this work main objectives, dedicated microelectronics together with customized software have been attained to functionalize, and empower the two-biomechatronic platforms. The bio-mechatronic system performance has been tested throughout a sufficient number of in vitro experiments.Open Acces

Mechanical Properties of Low Dimensional Materials

Recent advances in low dimensional materials (LDMs) have paved the way for unprecedented technological advancements. The drive to reduce the dimensions of electronics has compelled researchers to devise newer techniques to not only synthesize novel materials, but also tailor their properties. Although micro and nanomaterials have shown phenomenal electronic properties, their mechanical robustness and a thorough understanding of their structure-property relationship are critical for their use in practical applications. However, the challenges in probing these mechanical properties dramatically increase as their dimensions shrink, rendering the commonly used techniques inadequate. This Dissertation focuses on developing techniques for accurate determination of elastic modulus of LDMs and their mechanical responses under tensile and shear stresses. Fibers with micron-sized diameters continuously undergo tensile and shear deformations through many phases of their processing and applications. Significant attention has been given to their tensile response and their structure-tensile properties relations are well understood, but the same cannot be said about their shear responses or the structure-shear properties. This is partly due to the lack of appropriate instruments that are capable of performing direct shear measurements. In an attempt to fill this void, this Dissertation describes the design of an inexpensive tabletop instrument, referred to as the twister, which can measure the shear modulus (G) and other longitudinal shear properties of micron-sized individual fibers. An automated system applies a pre-determined twist to the fiber sample and measures the resulting torque using a sensitive optical detector. The accuracy of the instrument was verified by measuring G for high purity copper and tungsten fibers. Two industrially important fibers, IM7 carbon fiber and Kevlar® 119, were found to have G = 17 and 2.4 GPa, respectively. In addition to measuring the shear properties directly on a single strand of fiber, the technique was automated to allow hysteresis, creep and fatigue studies. Zinc oxide (ZnO) semiconducting nanostructures are well known for their piezoelectric properties and are being integrated into several nanoelectro-mechanical (NEMS) devices. In spite of numerous studies on the mechanical response of ZnO nanostructures, there is not a consensus in its measured bending modulus (E). In this Dissertation, by employing an all-electrical Harmonic Detection of Resonance (HDR) technique on ZnO nanowhisker (NW) resonators, the underlying origin for electrically-induced mechanical oscillations in a ZnO NW was elucidated. Based on visual detection and electrical measurement of mechanical resonances under a scanning electron microscope (SEM), it was shown that the use of an electron beam as a resonance detection tool alters the intrinsic electrical character of the ZnO NW, and makes it difficult to identify the source of the charge necessary for the electrostatic actuation. A systematic study of the amplitude of electrically actuated as-grown and gold-coated ZnO NWs in the presence (absence) of an electron beam using an SEM (dark-field optical microscope) suggests that the oscillations seen in our ZnO NWs are due to intrinsic static charges. In experiments involving mechanical resonances of micro and nanostructured resonators, HDR is a tool for detecting transverse resonances and E of the cantilever material. To add to this HDR capability, a novel method of measuring the G using HDR is presented. We used a helically coiled carbon nanowire (HCNW) in singly-clamped cantilever configuration, and analyzed the complex (transverse and longitudinal) resonance behavior of the nonlinear geometry. Accordingly, a synergistic protocol was developed which (i) integrated analytical, numerical (i.e., finite element using COMSOL ®) and experimental (HDR) methods to obtain an empirically validated closed form expression for the G and resonance frequency of a singly-clamped HCNW, and (ii) provided an alternative for solving 12th order differential equations. A visual detection of resonances (using in situ SEM) combined with HDR revealed intriguing non-planar resonance modes at much lower driving forces relative to those needed for linear carbon nanotube cantilevers. Interestingly, despite the presence of mechanical and geometrical nonlinearities in the HCNW resonance behavior, the ratio of the first two transverse modes f2/f1 was found to be similar to the ratio predicted by the Euler-Bernoulli theorem for linear cantilevers

MEMS Piezoresistive Micro-Cantilever Arrays for Sensing Applications

In several application fields there is an increasing need for a diffused on-field control of parameters able to diagnosis potential risks or problems in advance or in early stages in order to reduce their impact. The timely recognition of specific parameters is often the key for a tighter control on production processes, for instance in food industry, or in the development of dangerous events such as pollution or the onset of diseases in humans. Diffused monitoring can be hardly performed with traditional instrumentation in specialised laboratories, due to the time required for sample collection and analysis. In all applications, one of the key-points for a successful solution of the problem is the availability of detectors with high-sensitivity and selectivity to the chemical or biochemical parameters of interest. Moreover, an increased diffused on-field control of parameters can be only achieved by replacing the traditional costly laboratory instrumentations with a larger number of low cost devices. In order to compete with well-known and established solution, one of main feature of new systems is the capability to perform specific tests on the field with fast response times; in this perspective, a fast measurement of reduced number of parameters is to be preferred to a straightforward “clone” of laboratory instrumentation. Moreover, the detector must also provide robustness and reliability for real-world applications, with low costs and easiness of use. In this paradigm, MEMS technologies are emerging as realisation of miniaturised and portable instrumentation for agro-food, biomedical and material science applications with high sensitivity and low cost. In fact, MEMS technologies can allow a reduction of the manufacturing cost of detectors, by taking advantage of the parallel manufacturing of large number of devices at the same time; furthermore, MEMS devices can be potentially expanded to systems with high level of measurement parallelism. Device costs are also a key issues when devices must be for “single use”, which is a must in application where cross-contamination between different measurement is a major cause of system failure and may cause severe consequences, such as in biomedical application. Among different options, cantilever micro-mechanical structures are one of the most promising technical solution for the realisation of MEMS detectors with high sensitivity. This thesis deals with the development of cantilever-based sensor arrays for chemical and biological sensing and material characterisation. In addiction to favourable sensing properties of single devices, an array configuration can be easily implemented with MEMS technologies, allowing the detection of multiple species at the same time, as well as the implementation of reference sensors to reject both physical and chemical interfering signals. In order to provide the capability to operate in the field, solution providing simple system integration and high robustness of readout have been preferred, even at the price of a lower sensitivity with respect to other possibilities requiring more complex setups. In particular, piezoresistive readout has been considered as the best trade-off between sensitivity and system complexity, due to the easy implementation of readout systems for resistive sensors and to their high potential for integration with standard CMOS technologies. The choice has been performed after an analysis of mechanical and sensing properties of microcantilever, also depending of technological options for their realisation. As case-studies for the development of cantilever devices, different approaches have been selected for gas sensing applications, DNA hybridisation sensing and material characterisation, based on two different technologies developed at the BioMEMS research unit of FBK (Fondazione Bruno Kessler - Center for Materials and Microsystems, Trento). The first process, based on wet-etching bulk micromachining techniques, has provided 10 µm-thick silicon microcantilevers while the second technology, based on Silicon-On-Insulator (SOI) wafer, has provided a reduction of device thickness, thus resulting in an increase of sensitivity. Performances of devices has been investigated by analytical and numerical modelling of both structures and readout elements, in order to optimise both fabrication technology and design. In particular, optimal implant parameters for the realisation of piezoresistors have been evaluated with process simulation with Athena Silvaco simulation software, while ANSYS has been used to analyse the best design for devices and the effect of some technology-related issues, such as the effect of underetch during the release of the beams or residual stresses. Static and modal analysis of cantilever bending in different conditions have been performed, in order to evaluate the mechanical performances of the device, and later results have been compared with the experimental characterisation. With regard to gas sensing applications, the development has been oriented to resonant sensors, where the adsorption of analytes on a adsorbent layer deposited on the cantilever leads to shift of resonance frequency of the structure, thus providing a gravimetric detection of analytes. The detection of amines, as markers of fish spoilage during transport, has been selected as a case-study for the analysis of these sensors. The sensitivity of devices has been measured, with results compatible with the models. Cantilever structures are also suitable for bioaffinity-based applications or genomic tests, such as the detection of specific Single Nucleotide Polymorphisms (SNPs) that can be used to analyse the predisposition of individuals to genetic-based diseases. In this case, measurements are usually performed in liquid phase, where viscous damping of structures results in a severe reduction of resonance quality factor, which is a key-parameter for the device detection limit. Then, cantilever working in “bending mode” are usually preferred for these applications. In this thesis, the design and technologies have been optimised for this approach, which has different requirements with respect to resonant detectors. In fact, the interaction of target analytes with properly functionalised surfaces results in a bending of the cantilever device, which is usually explained by a number of mechanism ranging from electrostatic and steric interaction of molecules to energy-based considerations. In the case of DNA hybridisation detection, the complexity of the molecule interactions and solid-liquid interfaces leads to a number of different phenomena concurring in the overall response. Main parameters involved in the cantilever bending during DNA hybridisation has been studied on the basis of physical explanations available in the literature, in order to identify the key issues for an efficient detection. Microcantilever devices can play a role also in thin film technologies, where residual stresses and material properties in general need to be accurately measured. Since cantilever sensors are highly sensitive to stress, their use is straightforward for this application. Moreover, apart from their sensitivity, they also have other advantages on other methods for stress measurements, such as the possibility to perform on-line measurements during the film deposition in an array configuration, which can be useful for combinatorial approaches for the development of thin film materials libraries. In collaboration with the Plasma Advanced Materials (PAM) group of the Bruno Kessler Foundation, the properties of TiO2 films deposited by sputtering has been measured as a case study for these applications. In addiction to residual stress, a method for measuring the Young’s modulus of the deposited films has been developed, based on the measurement by means of a stylus profilometer of beam stiffness increase due to TiO2 film. The optimal data analysis procedure has been evaluated in order to increase the efficiency of the measurement. In conclusion, this work has provided the development of MEMS-based microcantilever devices for a range of different applications by evaluating the technological solutions for their realisation, the optimisation of design and testing of realised devices. The results validate the use of this class of devices in applications where high sensitivity detectors are required for portable analysis systems

Array atomic force microscopy for real-time multiparametric analysis.

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks

Alternative piezoresistor designs for maximizing cantilever sensitivity.

Over the last 15 years, researchers have explored the use of piezoresistive microcantilevers/resonators as gas sensors because of their relative ease in fabrication, low production cost, and their ability to detect changes in mass or surface stress with fairly good sensitivity. However, existing microcantilever designs rely on irreversible chemical reactions for detection and researchers have been unable to optimize symmetric geometries for increased sensitivity. Previous work by our group showed the capability of T-shaped piezoresistive cantilevers to detect gas composition using a nonreaction-based method – viscous damping. However, this geometry yielded only small changes in resistance. Recently, computational studies performed by our group indicated that optimizing the geometry of the base piezoresistor increases device sensitivity up to 700 times. Thus, the focus of this work is to improve the sensitivity of nonreaction-based piezoresistive microcantilevers by incorporating asymmetric piezoresistive sensing elements in a new array design. A three-mask fabrication process was performed using a 4 silicon-on-insulator wafer. Gold bond pads and leads were patterned using two optical lithography masks, gold sputtering, and acetone lift-off techniques. The cantilevers were patterned with electron-beam lithography and a dry etch masking layer was then deposited via electronbeam evaporation of iron. Subsequently, the silicon device layer was deep reactive ion etched (DRIE) to create the vertical sidewalls and the sacrificial silicon dioxide layer was removed with a buffered oxide etch, completely releasing the cantilever structures. Finally, the device was cleaned and dried with critical point drying to prevent stiction of the devices to the substrate. For the resonance experiments, the cantilevers were driven electrostatically by applying an AC bias, 10 Vpp, to the gate electrode. A DC bias of 10 V was placed across the piezoresistor in series with a 14 kÙ resistor. The drive frequency (0 – 80 kHz) was swept until the cantilever resonated at its natural frequency, which occurred when the output of the lock-in amplifier reached its maximum. These devices have been actuated to resonance under vacuum and their resonant frequencies and Qfactors measured. The first mode of resonance for the asymmetric cantilevers was found to range between 40 kHz and 63 kHz, depending on the piezoresistor geometry and length of the cantilever beam. The redesigned piezoresistive microcantilevers tested yielded static and dynamic sensitivities ranging from 1-6 Ù/Ìm and 2-17 Ù/Ìm displacement, respectively, which are 40 –730 times more sensitive than the best symmetric design previously reported by our group. Furthermore, the Q-factors ranged between 1700 and 4200, typical values for MEMS microcantilevers

Cantilever Array Platform for Quantitative Biological Analysis

RÉSUMÉ L'objectif de ce projet est de développer un réseau de microcapteurs pour collecter des données biologiques quantitatives. Ces types de données peuvent être utilisés dans divers domaines, notamment pour l'analyse cellulaire et moléculaire, la détection d’interactions biologiques spécifiques, la surveillance de maladies et la découverte de médicaments. Les capteurs proposés possèdent des réseaux de « cantilevers » qui convertissent les interactions biologiques en variations mécaniques et électriques. Ces capteurs peuvent avoir une sensibilité élevée et ont montré leurs efficacités dans diverses applications. De plus, leur utilisation permet de concevoir un système à haut débit pour la détection en temps réel de diverses paramètres. Afin de développer ces capteurs, un logiciel multiphysique (COMSOL) a été utilisé pour modéliser les « cantilevers » et plusieurs simulations électromécaniques ont été réalisées pour atteindre une conception appropriée. Deux méthodes de lecture, piezorésistive et capacitive, ont été choisies pour être utilisées avec les capteurs. Les deux capteurs ont été fabriqués par le biais de CMC Microsystems; le processus PolyMUMPs a été employé pour la fabrication de réseaux de capteurs capacitifs, et les capteurs piézorésistifs, quant à eux, ont été développés par le processus de MetalMUMPs. Enfin, les capteurs fabriqués ont été caractérisés suivant différentes étapes incluant l’interferometrie afin d'assurer leur fonctionnalité. Sur la base des résultats de simulation et de caractérisation obtenus, ces capteurs peuvent être utilisés pour élaborer une plateforme haut débit à bas coût pour diverses applications biologiques.----------ABSTRACT The objective of the present project is to develop an array of microsensors for gathering cellular and molecular quantitative biological data. Such data can be used in various fields including cellular and molecular analysis, detection of specific biological interactions, monitoring diseases, and drug discovery. The proposed sensing platform in this project can convert biological interactions into mechanical variations and subsequently converts the mechanical variations to electrical ones. This platform offers the advantage of high sensitivity, real time measurement, high throughput sensing array suitable for fundamental studies as well as clinical applications. We modeled the operation of cantilevers using COMSOL multiphysics software. These simulation techniques can efficiently be used to choose the suitable design and dimensions of cantilevers. Two readout methods, piezoresistive and capacitive, have been chosen to be used along with sensors. Both sensors were fabricated through CMC Microsystems; PolyMUMPs process was employed for fabrication of capacitive sensor array and piezoresistive sensors were developed by MetalMUMPs process. The functionality of cantilevers and their incorporated sensors were characterized through different techniques including interferometry.Based on these simulation and characterization results, the proposed sensors can be good candidate for developing a low cost, high throughput platform for various biological applications