A new authentication method employing a laser and a scanner is proposed to improve image contrast of the finger vein and to extract blood flow pattern for liveness detection. A micromirror reflects a laser beam and performs a uniform raster scan. Transmissive vein images were obtained, and compared with those of an LED. Blood flow patterns were also obtained based on speckle images in perfusion...

An overview of the current state of the art in scanning micromirror technology for switching, imaging, and beam steering applications is presented. The requirements that drive the design and fabrication technology are covered. Electrostatic, electromagnetic, and magnetic actuation techniques are discussed as well as the motivation toward combdrive configurations from parallel plate configuratio...

We demonstrate a new technique for selectively growing gold nanoparticles on a patterned three-dimensional (3D) polymer microstructure. The technique integrates 3D direct writing of heterogeneous microstructures with nanoparticle synthesis. A digital micromirror device is employed as a dynamic mask in the digital projection photopolymerization process to build the heterogeneous microstructure l...

A driving scheme using a pair of differential voltages (Vx, Vy) over a bias voltage is proposed to linearize the dc characteristic (angle versus voltage) of a two-axis MEMS scanner. The micromirror has a gimbal-less structure and is driven by vertical comb-drive actuators in conjunction with a leverage mechanism. At an optimal bias voltage of 53 V, a linear optical scan range of ±3.2◦ is achiev...

We report on the synergy of an integrated ultrasound (US) and photoacoustic (PA) probe system for intravascular imaging. The combined dual-modality probe is based on a 39 MHz ring-shaped US transducer which detects both US echoes and laser-generated PA signals. By combining optical fiber, US transducer, and micromirror, we can obtain intravascular cross-sectional B-scan images by internal illum...

Femtosecond laser-induced backward transfer of transparent photopolymers is demonstrated in the solid state, assisted by a digital micromirror spatial light modulator for producing shaped deposits. Through use of an absorbing silicon carrier substrate, we have been able to successfully transfer solid-phase material, with lateral dimensions as small as ~6 μm. In addition, a carrier of silicon in...

By switching between two tilt angles MEMS mirrors can be used to produce spatial light patterns. This enables the Digital Micromirror Display (DMD, Texas Instruments) chip to produce the images found in some data projectors. In this paper we will show how these images can be converted into electrical patterns. We use the electrical gradients in these patterns to control the movement of particle...