Piotr Kunicki

High-resolution and wide-bandwidth light intensity fiber optic displacement sensor for MEMS metrology

We report on the design, properties, and applications of a high-resolution and wide-bandwidth light intensity fiber optic displacement sensor for microelectromechanical system (MEMS) metrology. There are two types of structures that the system is dedicated to: vibrating with both high and low frequencies. In order to ensure high-frequency and high-resolution measurements, frequency down mixing and selective signal processing were applied. The obtained effective measuring bandwidth ranges from single hertz to 1 megahertz. The achieved resolution presented here is 116  pm/Hz1/2 and 138  pm/Hz1/2 for low-frequency and high-frequency operation modes, respectively, whereas the measurement of static displacement is 100 μm.

Thermal nanometrology using piezoresistive SThM probes with metallic tips

In this paper we present design and application of novel piezoresistive scanning thermal microscopy (SThM) probes. The proposed probe integrates a piezoresistive deflection sensor and thermally active, resistive nanosize tip. Manufacturing technology includes standard silicon MEMS/CMOS processing and sophisticated postprocessing using Focus Ion Beam milling. Authors also describe dedicated measurement technique in order to perform quantitative nanoscale thermal probing. Performance of the developed thermal probes is validated by test scans (topography and temperature distribution) of silicon nanoresistors supplied with current.

Magnetoelectric versus thermal actuation characteristics of shear force AFM probes with piezoresistive detection

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.

Soft lithography processing of fresnel lens for on-chip applications

Soft lithography and UV-NIL are important technologies for micro- and nano- structures replication [1]. It is possible to adapt surface structures preparation for many applications regarding e.g. opto-fluidic on-chip microscopy, wetting or reflection properties [2]. Light microscopy has been one of the most common tools in biological research, because of its high resolution and non-invasive nature of the light. Fresnel lens can be used in passive and active high quality polymer-based on-chip components for integrated photonics circuits [3]. In presented soft lithography technique the various materials were used for Fresnel lens replication: PDMS, h-PDMS and thiol-ene-epoxy resin. Mentioned polymers are characterized by high flexibility and transparency with minimal color. The silicon matrices replication process involves two main steps: anti-adhesive layer preparation and polymer deposition. The influence of structures geometry on the optical properties Fresnel lens has been investigated. The topography of obtained replicas was characterized using the atomic force microscopy (AFM) and scanning electron microscopy (SEM). The efficiency of light focus of the selected wavelength has been checked by intensity measurement using a standard optical microscope. As a result of replication 10□m diameter Fresnel lenses have been prepared.

Manufacturing, measurement and control of MEMS / NEMS electrostatically driven structures

Increased interest in micro-and nano-electromechanical systems (MEMS and NEMS) entail the development of reliable measurement techniques for the basic parameters of the designed and manufactured devices. The proposed methodology should provide high resolution, wide frequency range and the possibility to investigate both mechanical and electrical parameters during inspection process. In this article authors present methods for manufacturing of electrostatic MEMS devices. Measurement techniques will be presented for specifying parameters such as resonant frequency, quality factor and sensitivity of the previously manufactured structures. Manufacturing techniques will be presented on the example of the micropusher structure, whereas measurement techniques will be presented on the example of the microgripper structure.