Zurich, Switzerland
Zurich, Switzerland

Time filter

Source Type

Lu Z.,Albert Ludwigs University of Freiburg | Poletkin K.,Albert Ludwigs University of Freiburg | Den Hartogh B.,FemtoTools GmbH | Wallrabe U.,Albert Ludwigs University of Freiburg | Badilita V.,Albert Ludwigs University of Freiburg
Sensors and Actuators, A: Physical | Year: 2014

We present herewith detailed theoretical modeling coupled with experimental analysis of a micromachined inductive suspension (MIS). The reported MIS is based on two coaxial 3D solenoidal microcoils realized using our wirebonding technology. The two coils are excited using an AC signal with 180° phase-shift and a conductive proof mass (PM) is stably levitated on top of the coils. Using a micromechanical displacement sensor, we experimentally derive the lateral, vertical and angular stiffness constants of our MIS. Based on the analytical model presented here, we discuss the stability of the levitated proof mass as a function of the geometrical parameters of the design. We further test our model by applying it to another previously reported MIS structure realized using planar technology, providing stability diagrams as well as design guidelines for further developments of the micromachined inductive suspension as, for instance, miniature rotating gyroscopes. © 2014 Elsevier B.V. All rights reserved.


Arcese L.,University of Orléans | Fruchard M.,University of Orléans | Beyeler F.,FemtoTools GmbH | Ferreira A.,University of Orléans | Nelson B.J.,ETH Zurich
Proceedings - IEEE International Conference on Robotics and Automation | Year: 2011

A microrobot consisting of a polymer binded aggregate of ferromagnetic particles is controlled using a Magnetic Resonance Imaging (MRI) device in order to achieve targeted therapy. The primary contribution of this paper is the design of an adaptive backstepping controller coupled with a high gain observer based on a nonlinear model of a microrobot in a blood vessel. This work is motivated by the difficulty in accurately determining many biological parameters, which can result in parametric uncertainties to which model-based approaches are highly sensitive. We show that the most sensitive parameter, magnetization of the microrobot, can be measured using a Micro-Electro- Mechanical Systems (MEMS) force sensor, while the second one, the dielectric constant of blood, can be estimated on line. The efficacy of this approach is illustrated by simulation results. © 2011 IEEE.


Taprogge J.L.M.,Center Suisse Delectronique Et Of Microtechnique | Taprogge J.L.M.,ETH Zurich | Nelson B.J.,ETH Zurich | Beyeler F.,FemtoTools GmbH
IEEE Transactions on Components, Packaging and Manufacturing Technology | Year: 2013

System-in-package (SiP) devices are increasingly becoming popular. When they are packaged using controlled collapse chip connection or derived processes, precise substrate heating at the land location is necessary. Currently, this is commonly achieved by heating the chip-handling probe. This approach restrains free motion of the chip and inhibits self-alignment of the chip to the substrate. Alternatively, the system is heated in a furnace. We present a method that heats the substrate locally at the desired spot while precisely controlling the temperature. This is achieved by embedding a Joule heater into the substrate. Additional sensors are not required because the change of the resistance of the heating, which reflects the change in temperature, is closely monitored. Because the temperature is determined inside the substrate, it provides accurate feedback of the solder's temperature. The method has been implemented and tested in an SiP microelectromechanical systems assembly process. It has proven to be a viable alternative to current methods, and features fast, localized, and tightly controlled heating and does not restrict the chip's free motion, thereby allowing chip self-alignment. Since the heating is integrated into the substrate, it also does not interfere with other components and requires no housing to protect the operators against optical radiation. Our method can be implemented at virtually no variable cost and with very low equipment costs. © 2011-2012 IEEE.


Grant
Agency: European Commission | Branch: FP7 | Program: CP | Phase: ICT-2007.3.6 | Award Amount: 3.89M | Year: 2008

The NANOMA project aims at proposing novel controlled nanorobotic delivery systems which will be designed to improve the administration of drugs in the treatment and diagnosis of breast cancer. Breast cancer is diagnosed in 1.2 million men and women globally every year and kills 500,000. The NANOMA project proposes a magnetic nanocapsule steering approach that relies on improved gradient coils for Magnetic Resonance Imaging (MRI) systems. MRI systems also provide concentration and tracking information, real-time interventional capabilities and are already widespread in hospitals. It is based on fundamental techniques and methods for the propulsion, navigation and effective targeted delivery of coated ferromagnetic capsules in the cardiovascular system through the induction of force from magnetic gradients generated by a clinical MRI. This proposed NANOMA platform will be a valuable tool to help enhance the efficiency of breast cancer treatments while improving patients recovery time.The project rests on the pillar of six work packages (WPs) , which are further divided into subprojects (SPs). Substantial RandD activities are carried out in WP1-WP4 with the goal to design, model and control the microcapsule. In WP5-WP6 new biocarriers and biosensors made of ferromagnetic particles and special functionalized materials reacting to environmental changes in infected cancer cells are being investigated. As proof-of-concept, an in-vivo breast cancer cell detection platform is realized and evaluated in WP7. WP8 deals with the effective Europe-wide exploitation and dissemination of the project results. Finally, WP9 manages the project.The project consortium gives almost a guarantee for the projects success.


A system (100) for testing MEMS-structures comprises- a microforce sensor (1);- two or more multi-axis micropositioning units (2);- at least one or electrical probe (4);- a sample holder (5) on which a MEMS-structure (6) is mounted. At least one of said multi-axis micropositioning units (2) is motorized and at least one additional micropositioning unit (2) is equipped with at least one electrical probe (4) to apply electrical signals or to measure electrical signals at one or multiple locations on the MEMS structure (6). The system with the before mentioned components allows a combined electrical and probe-based mechanical testing of MEMS-structures (6).


This invention includes a microfabricated sensor (100) for micro- and nanomechanical testing and nanoindentation. The sensor (100) includes a force sensing capacitive comb drive (8) for the sensing of force applied to a sample, a position sensing capacitive comb drive (9) for the sensing of the position of a sample and a microfabricated actuator to apply a load to the sample. All sensor components mentioned above are monolithically integrated on the same silicon MEMS chip.


The mechanical characterization system includes three main parts: A sub-millinewton resolution capacitive force sensor, at least one micromanipulator with position measurement capabilities, and a microscope. The sensitive axis of the force sensor is adjustably connected via adaptor pieces to the micromanipulator at any angular orientation relative to the sample holder.


Most mechanical tests (compression testing, tensile testing, flexure testing, shear testing) of samples in the sub-mm size scale are performed under the observation with an optical microscope or a scanning electron microscope. However, the following problems exist with prior art force sensors as e.g they cannot be used for in-plane mechanical testing (a- and b-direction) of a sample; they cannot be used for vertical testing (c-direction) of a sample. In order to overcome the before mentioned drawbacks the invention comprises the following basic working principle: A force is applied to the probe (2) at the probe tip (1) of the sensor. The force is transmitted by the sensor probe (2) to the movable body (3) of the sensor. The movable body is elastically suspended by four folded flexures (4), which transduce the force into a deflection dx. This deflection is measured by an array of capacitor electrodes, called capacitive comb drive (6).


A micro fabricated sensor for micro-mechanical and nano-mechanical testing and nano-indentation. The sensor includes a force sensing capacitive comb drive for the sensing of a force applied to a sample, a position sensing capacitive comb drive for the sensing of the position of a sample and a micro fabricated actuator to apply a load to the sample. All the sensor components mentioned above are monolithically integrated on the same silicon MEMS chip.


A system for testing MEMS-structures includes a microforce sensor, two or more multi-axis micropositioning units, at least one electrical probe and a sample holder on which a MEMS-structure is mounted. At least one of the multi-axis micropositioning units is motorized and at least one additional micropositioning unit is equipped with at least one electrical probe to apply electrical signals or to measure electrical signals at one or multiple locations on the MEMS structure. The system with the aforementioned components allows a combined electrical and probe-based mechanical testing of MEMS-structures.

Loading FemtoTools GmbH collaborators
Loading FemtoTools GmbH collaborators