We present a three-dimensional (3D) endoscopic optical coherence tomography (OCT) system based on a dual-axis scanning microelectromechanical system (MEMS) mirror. The diameter of the MEMS mirror was 1.2mm and both axes were capable of scanning greater than 20° with linearity. The endoscopic MEMS probe was integrated with an OCT system and volume images were obtained at a rate of 3frames∕s by means of two-axis lateral scanning combined with an axial scan. In the initial investigations, 3D OCT images of healthy rabbit trachea as well as images of normal and cancerous regions of hamster cheek pouch tissue were obtained.

Microfluidic systems based on polydimethylsiloxane (PDMS) have gained popularity in recent years. However, microelectrode patterning on PDMS to form biosensors in microchannels remains a worldwide technical issue due to the hydrophobicity of PDMS and its weak adhesion to metals. In this study, an additive technique using inkjet-printed silver nanoparticles to form microelectrodes on PDMS is presented. (3-Mercaptopropyl)trimethoxysilane (MPTMS) was used to modify the surface of PDMS to improve its surface wettability and its adhesion to silver. The modified surface of PDMS is rendered relatively hydrophilic, which is beneficial for the silver droplets to disperse and thus effectively avoids the coalescence of adjacent droplets. Additionally, a multilevel matrix deposition (MMD) method is used to further avoid the coalescence and yield a homogeneous pattern on the MPTMS-modified PDMS. A surface wettability comparison and an adhesion test were conducted. The resulting silver pattern exhibited good uniformity, conductivity and excellent adhesion to PDMS. A three-electrode electrochemical biosensor was fabricated successfully using this method and sealed in a PDMS microchannel, forming a lab-on-a-chip glucose biosensing system.

This paper presents a fabrication process that integrates polysilicon surface micromachining and deep reactive ion etching (DRIE) bulk silicon micromachining. The process takes advantage of the design flexibility of polysilicon surface micromachining and the deep silicon structures possible with DRIE. As a demonstration, a torsional actuator driven by a combdrive moving in the out-of-plane direction, consisting of polysilicon fingers and bulk silicon fingers, has been fabricated. The integrated process allows the combdrive to be integrated with any structure made by polysilicon surface micromachining. [433]Index Terms-Asymmetric combdrive, electrostatic torsional actuator, integrated polysilicon and deep reactive ion etching (DRIE) bulk silicon micromachining, levitation, parallel-plate actuator.

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