Ioan Alexandru Ivan

Institut FEMTO-ST | FEMTO ST · Department of Automatic Control and Micro-Mechatronic Systems (AS2M)

Starting from ancient age, physical phenomena have become more and more intriguing for humanity, and always evolutionary steps have been in strong connection with the idea of understanding their importance for a better life. Not once, the open minds were considered outrageous for their theories or the concepts and hypothesis regarding the reasons f...

This paper proposes a self-sensing measurement technique to perform the precise estimation of the displacements along two axes in a two-degrees of freedom (2-DOF) piezoelectric actuator. For that, a new electrical circuit scheme which permits charge amplification is first proposed to match the different electrodes combination of the 2-DOF actuator....

This paper sets forth to study and demonstrate the usability of an emerging piezoelectric material, called Lead Magnesium Niobate–Lead Titanate (PMN–PT), as a potential actuator for dexterous micro-manipulation. For this purpose, a generic structure called a duobimorph cantilever is studied. The proposed design takes advantage of a specific transve...

This paper presents how a Lead Magnesium Niobate – Lead Titanate (PMN-PT) based actuator, poled and cut along the [001] crystalline direction, can be used as an integrated actuator in a Micro Opto Electro Mechanical System (MOEMS). This cut was chosen as it has been proved to present piezoelectric coefficients that surpass 4500pm/V. This makes PMN-...

This paper presents how a Lead Magnesium Niobate – Lead Titanate (PMN-PT) based actuator, poled and cut along the [001] crystalline direction, can be used as an integrated actuator in a Micro Opto Electro Mechanical System (MOEMS). This cut was chosen as it has been proved to present piezoelectric coefficients that surpass 4500pm/V. This makes PMN-...

This paper presents how a Lead Magnesium Niobate – Lead Titanate (PMN-PT) based actuator, poled and cut along the [001] crystalline direction, can be used as an integrated actuator in a Micro Opto Electro Mechanical System (MOEMS). This cut was chosen as it has been proved to present piezoelectric coefficients that surpass 4500pm/V. This makes PMN-...

Self-sensing technique consists of using an actuator as a sensor at the same time. This is possible for most actuators with physically reversible principle such as piezoelectric materials. The main advantages of self-sensing are: 1) the embeddability of the measurement technique, and 2) its low cost as no additional sensor is required. This paper p...

This paper investigates the use of a PMN-PT [001] piezoelectric actuator to be integrated in smart Micro-Opto-Electrical-Mechanicals Systems (MOEMS). Unlike most piezoelectric materials, PMN-PT [001] can generate large-stroke out-of-plane displacement. This is due to its very high longitudinal piezoelectric coefficient of up to 4500pm/V. After an i...

This paper investigates the use of a PMN-PT [001] piezoelectric actuator to be integrated in smart Micro-Opto-Electrical-Mechanicals Systems (MOEMS). Unlike most piezoelectric materials, PMN-PT [001] can generate large-stroke out-of-plane displacement. This is due to its very high longitudinal piezoelectric coefficient of up to 4500pm/V. After an i...

In situ physical micromanipulation technology of colloids inside microfluidic devices can open various lab-on-a-chip applications. This paper reports a development of mobile microrobotic manipulators in microfluidic devices (MRMF). The microrobotic agents are made up of a PMN-PT and a nickel bilayer, then integrated inside a multiport microfluidic...

This paper presents the modeling, fabrication, FEM simulation and validation of a PMN-PT [001], bulk micro-actuator intended for integration in smart Micro-Opto-Electrical-Mechanicals Systems (MOEMS). Unlike the majority of piezoelectric materials, PMN-PT [001] has the ability to generate large-stroke out-of-plane actuation; this is due to its high...

Recent advances in micro/nanotechnologies and microelectromechanical systems have enabled micromachined mobile agents. Highly dynamic mobile microrobots are believed to open the gate for various future applications. However, at the submillimeter scale, the adhesion effects dominate physics, especially in the air environment. Although many studies h...

When related to a single and good contrast object or a laser spot, position sensing, or sensitive, detectors (PSDs) have a series of advantages over the classical camera sensors, including a good positioning accuracy for a fast response time and very simple signal conditioning circuits. To test the performance of this kind of sensor for microroboti...

In the attempt to find the appropriate micromanufacturing technology of PMN–PT (lead magnesium niobate–lead titanate) piezo material, whose MEMS-related applications look promising, two methods are investigated: excimer laser ablation (using KrF gas) and inductively coupled plasma (ICP) dry etching, also known as DRIE (using Ar/C4F8 gases). The pap...

A new microgripper dedicated to micromanipulation and microassembly tasks is presented in this paper. Based on a new actuator, called thermo-piezoelectric actuator, the microgripper presents both a high range and a high positioning resolution. The principle of the microgripper is based on the combination of the thermal actuation (for the coarse pos...

Most of the actual MEMS (Micro-Electro-Mechanical Systems) are Silicon capacitive devices. The reported research provides the means for approaching towards novel concepts combining silicon technology with piezoelectric materials into Piezo-MEMS systems. The presented technology is based on the bonding and patterning of bulk PMN-PT piezoelectric mat...

This chapter aims to develop a self-sensing technique to measure the displacement and the force in piezoelectric microactuators dedicated to micromanipulation and microassembly contexts. In order to answer the requirements in these contexts, the developed self-sensing should perform a long duration measurement of constant signals (displacement and...

The paper documents the principle and experiments of the "2mm dash" winner at NIST IEEE Mobile Microrobotics Challenge held at ICRA2010 in Alaska [1]. Submission is made for the special session "ICRA Robot Challenge: Advancing Research Through Competitions". The new MagPieR microrobot was specially designed for breaking the speed record, providing...

During the last decade, the applications of PMN-PT spread significantly. Unlike PZT, the appropriate microtechnologies for PMN-PT Piezo-MEMS aren't fully documented in the literature. This paper deals with the PMN-PT etching by inductively coupled plasma (ICP) technique, also known as DRIE. The paper quantitatively presents the etching parameters o...

In this paper, we propose and model a new microvalve design based on a unimorph piezoelectric bending cantilever. When the piezoelectric structure is electrically driven, the valve opens with precise angles allowing smooth flow control. In order to understand the whole system dynamic behavior, a physical model is developed. While the developed mode...

This paper presents a new hybrid microactuator based on the combination of piezoelectric and thermal effects. The proposed actuator can perform both a high-stroke coarse positioning through the thermal actuation and a high-resolution fine positioning through the piezoelectric actuation. The microactuator structure is a unimorph piezoelectric cantil...

The advent of commercially available giant piezoelectric coefficient monocrystalline materials such as PMN-PT (lead magnesium niobate - lead titanate) or PZN-PT (lead zinc niobate - lead titanate) broadens the gate for silicon-integrated applications (PiezoMEMS). Becoming more compatible with microtechnology batch processes, further advances are ex...

The main objective of this paper is the dynamic self-sensing of the motion of piezoelectric actuators. The proposed measurement technique is afterwards used for a closed-loop control. Aiming to obtain a self-sensing scheme that estimates the transient and steady-state modes of the displacement, we extend a previous static self-sensing scheme by add...

This paper presents a new actuator based on a unimorph piezocantilever and on the thermal bimorph principle, called hybrid thermo-piezoelectric actuator. The main advantage of the proposed actuator is the high range of positioning from the thermal actuation and the high resolution and bandwidth from the piezoelectric one. A characterization and lin...

We present here the use of sensors, observers and self-sensing techniques to control piezoelectric actuators, particularly piezocantielevers. First, the feedback control with full measurements (all variables are measured) is presented. Because of the lack of convenient sensors for the microworld, nonfull measurements combined with observer techniqu...

This paper presents a new method of self-sensing both of the displacement and the external applied force at the tip of piezoelectric cantilevers. Integrated electric current across piezoelectric actuators is compensated against material nonlinearities (creep, hysteresis) to provide reliable information. We propose to compensate the hysteresis by us...

New giant piezoelectric factor materials such as PMN-PT and PZN-PT were researched during the last decade and are actually becoming commercially available. As they seem very attractive for actuator designs, we studied their potential in replacing PZT ceramics. In a first comparative approach, we tested a series of classic rectangular composite bimo...

Piezoelectric meso- and microactuator systems required for manipulation or assembly of microscale objects demand reliable force and/or displacement information. Available sensors are prone to dimension restrictions or precision limitation. Self-sensing method, based on the electric charge measurement, may represent a solution in terms of cost-effec...

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