This paper reports the micromachining technology developed for the fabrication of microfluidic devices for the biological research and also our recent development of on-chip manipulation and analysis of cells. Development of micromachining technologies such as deep glass etching using high-density plasmas has enabled us to fabricate highly functional microfluidic devices with precise microstruc...

Capacitive micromachined ultrasonic transducers ~CMUTs!, introduced about a decade ago, have been shown to be a good alternative to conventional piezoelectric transducers in various aspects, such as sensitivity, transduction efficiency, and bandwidth. In this paper, we discuss the principles of capacitive transducer operation that underlie these aspects. Many of the key features of capacitive u...

Laser micromachining has great potential as a MEMS (micro-electro-mechanical systems) fabrication technique because of its materials flexibility and 3D capabilities. The machining of deep polymer structures with complex, well-defined surface profiles is particularly relevant to microfluidics and micro-optics, and in this paper we review recent work on the use of projection ablation methods to f...

We have conducted experimental investigations for the micromachining of dielectrics (fused silica) using an integrated femtosecond (fs) and nanosecond (ns) dual-beam laser system at different time delays between the fs and ns pulses. We found that the maximum ablation enhancement occurs when the fs pulse is shot near the peak of the ns pulse envelope. Enhancements up to 13.4 times in ablation d...

This manuscript describes the use of water-soluble polymers for use as sacrificial layers in surface micromachining. Water-soluble polymers have two attractive characteristics for this application: 1) They can be deposited conveniently by spin-coating, and the solvent removed at a low temperature (95-150 degrees C), and 2) the resulting layer can be dissolved in water; no corrosive reagents or ...

In this work, an accelerating etching method for glass named thermal electrical modified etching (TEM etching) is investigated. Based on the identification of the effect in anodic bonding, a novel method for glass structure micromachining is proposed using TEM etching. To validate the method, TEM-etched glasses are prepared and their morphology is tested, revealing the feasibility of the new me...

Controlling microbial growth is crucial for many biomedical, pharmaceutical and food industry applications. In this paper, we used a femtosecond laser to microstructure the surface of chitosan, a biocompatible polymer that has been explored for applications ranging from antimicrobial action to drug delivery. The influence of energy density on the features produced on chitosan was investigated b...

In this paper, a novel piezoresistive accelerometer based on the piezoresistive effect of GaAs/Al0.4Ga0.6As thin films was designed. The piezoresistive accelerometer contains four suspended flexural beams and a central proof mass configuration. The piezoresistive effect of a piezoresistor or thin film was used to make a resistor changing the output that is proportional to applied acceleration. ...

Micromachining allows the formation of micrometer-sized regions of bare gold on the surface of a gold film supporting a self-assembled monolayer (SAM) of alkanethiolate. A second SAM forms on the micromachined surfaces when the entire system-the remaining undisturbed gold-supported SAM and the micromachined features of bare gold-is exposed to a solution of dialkyl disulfide. By preparing an ini...

Circular three-dimensional (3D) micropatterns with grooves and ridges of various sizes on the circumference of the structure were micromachined in polymethylmethacrylate, using proton beam micromachining. Fibroblasts were seeded in the center smooth nonpatterned surface of the circle. The circumference grooves could retard the outward spreading of cells after they became confluent in the centra...