Mohammad Maroufi

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We investigated the effects of microamperage electrical stimulation (MES) on the healing of skin incision in rabbits. Thirty male adult rabbits were randomly divided into sham-treated and experimental groups. Each group was divided into three subgroups, based on the duration of experiment (4, 7, and 15 days). A full-thickness incision was made on the skin(More)
There is a need for 2 DOF scanners in a variety of applications in nanotechnology, particularly in the Atomic Force Microscope (AFM). An ideal AFM stage should have a high resonance frequency, low cross coupling between the two perpendicular axes of motion and be capable of moving over a large range in either direction. To achieve these specifications,(More)
A 2-degree of freedom microelectromechanical systems nanopositioner designed for on-chip atomic force microscopy (AFM) is presented. The device is fabricated using a silicon-on-insulator-based process and is designed as a parallel kinematic mechanism. It contains a central scan table and two sets of electrostatic comb actuators along each orthogonal axis,(More)
A new microelectromechanical systems-based 2-degree-of-freedom (DoF) scanner with an integrated cantilever for on-chip atomic force microscopy (AFM) is presented. The silicon cantilever features a layer of piezoelectric material to facilitate its use for tapping mode AFM and enable simultaneous deflection sensing. Electrostatic actuators and electrothermal(More)
We demonstrate the application of internal model control for accurate tracking of spiral scan trajectories, where the reference signals are orthogonal sinusoids whose amplitudes linearly vary with time. The plant is a 2-D microelectromechanical system nanopositioner equipped with in situ differential electrothermal sensors and electrostatic actuators. This(More)
We propose a two-degree-of-freedom washout control structure for tracking of sinusoidal references in lightly damped structures subject to sensor drift and measurement noise. An algorithm is derived, assigning stable parameter intervals to a second-order washout damping compensator for a resonant plant with a single dominant mode. Simulation results(More)
The atomic force microscope (AFM) has been recognized as an invaluable tool for researchers working in a wide range of nanotechnology-related fields. The AFM is a mechatronic microscope that is able to interrogate the surface of physical samples to produce 3D images with atomic resolution. It typically contains a cantilever with a sharp probe tip of a few(More)
This paper presents the design, implementation, and control of a novel microelectromechanical system (MEMS) force sensor. The device features bidirectional electrostatic actuators and on-chip piezoresistive displacement sensors. For the fabrication, a standard silicon-on-insulator process is used. Due to the bidirectional geometry, the probe is able to(More)