In this work, we demonstrate all-electronically tunable terahertz quantum cascade lasers (THz QCLs) with MEMS tuner structures. A two-stage MEMS tuner device is fabricated by a commercial open-foundry process performed by the company MEMSCAP. This provides an inexpensive, rapid, and reliable approach for MEMS tuner fabrication for THz QCLs with a high-precision alignment scheme. In order to ele...

Piezoelectric force and position sensors provide high sensitivity but are limited at low frequencies due to their high-pass response which complicates the direct application of integral control. To overcome this issue, an additional sensor or low-frequency correction method is typically employed. However, these approaches introduce an additional first-order response that must be higher than the...

A novel algorithm is described and illustrated for high speed imaging of biopolymers and other stringlike samples using atomic force microscopy. The method uses the measurements in real-time to steer the tip of the instrument to localize the scanning area over the sample of interest. Depending on the sample, the scan time can be reduced by an order of magnitude or more while maintaining image r...

Non-contact interaction between two parallel flat surfaces is a central paradigm in sciences. This situation is the starting point for a wealth of different models: the capacitor description in electrostatics, hydrodynamic flow, thermal exchange, the Casimir force, direct contact study, third body confinement such as liquids or films of soft condensed matter. The control of parallelism is so de...

For tracking control of nanopositioning stages using piezoelectric actuators, controllers with integral action can be employed to robustly track a reference in the presence of hysteresis, creep, and plant parametric uncertainties. In any practical configuration of instrumentation for this application, saturations will be present. Thus, a controller with integral action is prone to windup, which...

− The most important principles, the basis and operation of heterodyne and homodyne interferometers are discussed. Their benefits and limitations are covered based on a metrological analysis. The resolution of interferometers can be determined by calculating the smallest resolvable distance increment. Also, it is shown here how the Abbe comparator principle can be fulfilled in all three measuri...

This paper reports on a visual servoing system capable of 2DOF nanopositioning using a novel multi-axis electrostatic MEMS (MicroElectroMechanical System) device. The high aspect ratio micromanipulator was fabricated using a high yield process with Deep Reactive Ion Etching (DRIE) on Silicon-On-Insulator (SOI) wafers, which produces larger electrostatic forces and requires lower actuation volta...

We present the realization and performance of a multiprobe microcontactor made of an array of metallic microcantilevers inserted in an atomic force microscope ~AFM!. This instrument permits simultaneous AFM imaging and electrical characterization of nanoscale devices. It is therefore well adapted for future generations of molecular devices. The probes are 2-mm-wide metallic cantilevers that are...