Microsystem Technology

Laser-Direct-Writing-Based 3D Micro-Printing Technology [ 下載 PDF ]

Chih-Lang Lin

The '3D printing' nowadays is a hot topic, which has become the key technology of 'The third industry revolution' in the world. The 3D printing is based on the process of making a three-dimensional solid object of virtually any shape with polymer or viscous materials by sliced working from a digital model. Such manufacture method has the advantages of convenience, rapid and intuition. 'Laser direct writing' is one of the 3D printing techniques in the form. This report introduces the principle and applications of the 'two-photon polymerization' which is the key technology of laser direct writing. Also the developments in the world and our recent works are presented in this report.

Nano-Sculptured Metal Films as Surface Enhanced Raman Spectroscopy (SERS) Sensor [ 下載 PDF ]

Ching-Wei Yu, Yung-Hsiang Wang, Yi-Jun Jen

The SERS (surface enhanced Raman spectroscopy) sensing substrate comprising silver nanopillars was fabricated using glancing angle deposition (GLAD) together with self-rotation substrate. The SERS-active substrate owns broadband and high absorption spectra for unpolarized incident rays in the visible and infrared wavelength regimes. One of non-selective herbicide (paraquat, PQ) widely used for chemical weed control was successfully detected using SERS technique. The silver film was used as the SERS (surface-enhanced Raman scattering) substrate to enlarge the Raman signals of paraquat at the wavelength of 514 nm. This work demonstrates the feasibility of the rapid detection method for the indentation of pesticide residue.

Applications of Thermal Bubble Powered Microactuator in Microfl uidic Biochips [ 下載 PDF ]

Ching-Fu Tsou, Cheng-Han Huang, Keh-Sin Tseng

Microfluidic chips have been widely used in biomedical applications such as detecting chemical reactions and biological features. The miniaturized system significantly reduces traditional feature sizes and improves complex apparatus to a chip; also including screening, separating, and transmitting functions. They require few samples to accomplish bio-analysis and effectively shorten the cycle time. In this work, we present the implementation of a thermal bubble actuated microfluidic chip with microvalve, micropump and micromixer for microparticle separation, based on a simple process with SOI wafer. Only two photolithography processes were required to provide an effective means of manufacturing the bulk microheater and high-aspect-ratio microchannel for microfluidic applications. The feasibility of a thermal bubble pumping fluid to manipulate a microbead with a diameter of 20 µm has also been verified by experiments. It is expected that the proposed microfluidic chip can be applied for the separation of cells, such as live cells in amniotic fluid.

Development of Piezoelectric Flexible Tactile Sensor for Detection of Tissue Hardness [ 下載 PDF ]

Cheng-Hsin Chuang, Tsan-Hsiu Li, Kun-Feng Lu, Chien-Liang Mu

Detecting the mechanical characteristic of tissues is a highly effective means of distinguishing between a cancerous lump and healthy tissues during minimally invasive surgery (MIS). Gastric submucosal tumors are difficult to diagnosis by endoscope due to tumors covered by normal gastric mucosa tissue. This presents a novel miniaturized tactile sensor for differentiating the hardness of elastomer under a gastric mucosa of pig. The flexible tactile sensor consists of two patterned flexible print circuits (FPCs) sandwiching a polymer piezoelectric film (PVDF) and a small steel ball embedded in a soft material (PDMS) on the FPC surface. Owing to the stiffness difference between a steel ball and PDMS material, the uneven stress distribution on piezoelectric film can be induced and varied with contact objects. Therefore, the ratio of voltage outputs between the inner and outer electrodes on the piezoelectric film can differentiate between the mechanical characteristics of a contact object. Experimental results indicate that the voltage ratio increases with the Young.s modulus of elastomer from 1 to 3 MPa. Additionally, the voltage ratio not only depends on elastomer Young.s modulus but also affects by the magnitude of normal force applied on tactile sensor. Consequently, capable of differentiating between soft tissues, the tactile sensor is thus highly promising for integration with a medical device for minimally invasive surgery.

Heavy Metal Ions Adsorption and Separation Based on Modifi ed Nanoporous Anodic Aluminum Oxide Structures [ 下載 PDF ]

Hsing-Cheng Chang, Ya-Hui Chen, An-Ting Lo

The modified nanoporous Anodic aluminum oxide (AAO) as sensing structures for adsorption of heavy metal ions removal from aqueous solution was developed by two-step anodization and surface modification processes. The chemiluminescence (CL) reaction of luminol-based mechanism for measuring selected ions concentration was achieved by using a three dimensional stacked centrifugal microfluidic system. The adsorbents of rhodanine monomer, activated alumina and activated carbon were immobilized onto the surface and internal pores of nanoporous AAO template as multi-filtration modified-AAO composite membrane exhibited excellent uniformities, high surface porosity, low nonspecific adsorption and good hydraulic permeability and can be used for enhancing adsorption and separation of heavy metal ions.

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Portable Anti-Blue Light Lens Measuring Device [ 下載 PDF ]

Der-Chin Chen, Siak Lim Lee, Han-Jie Lin

This study set up a portable measurement system for anti-blue light lens, its characteristic is using a light pulse modulator and filtering circuit technology to prevent ambient light interference and no need to used optical filters. Electronic Pulse wave signal by half-wave conversion circuit enables the microprocessor to do calculations. The system composed by the transmitter circuit, receiver circuit and signal processing circuit. The transmitter circuit use Darlington drive circuit to optimize the LED operating current, so that it can be obtain the strongest pulsed light. Through the experiment prove that transmittance measurement accuracy is up to 6%, the anti-blue lenses brown 20% (transmittance is 80%) , blue film antiblue light lenses having anti-blue light effect, and measuring obtain the object color deviation within 3%.

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The Technologies of Ground Mechanical Green Energy Harvesting [ 下載 PDF ]

Da-Yi Tsai, Cheng-Yan Yang, Yi-Hua Pan, Wun-Yi Yan, Chen-Ching Ting

Recently, a variety of natural disasters appear world widely, which seems to give human an ultimatum and show the result of overused earth energy. The polluted environment has caused the exceptional climate. Today, how to save energy and how to increase the use ratio of renewable energy are the serious topics. The currently focused technologies of renewable energy are for solar energy, wind energy, hydraulic energy, biomass energy, geothermal energy, ocean energy, ground mechanical green energy, etc., where the ground mechanical green energy is developed in the recent years. The so-called ground mechanical green energy here is caused by the normal forces which are supported by walking people and running vehicles. In general, the ground mechanical green energy is the pulse energy which is diffi cult to be used. Even so, the summed ground mechanical green energy is extremely large and many technologies are therefore developed for harvesting. For example, piezoelectric effect, electromagnetic induction, varying capacitance, pulse to rotation, heat/sound electricity generation technologies, and so on. This study is focused on the ground mechanical green energy harvesting. Using preliminary study to estimate the energy and show its value in this work.

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The Design of Visual Evoked Potential-Based Brain Computer Interface with High Information Transfer Rate [ 下載 PDF ]

Po-Lei Lee, Kuo-Kai Shyu

In this article, we introduce a novel visual evoked potential (VEP)-based brain computer interface (BCI) which allows paralyzed patients to communicate with external environments, independent of peripheral nerves and muscles. In the present systems, flashing stimuli, such as digits or letters, are displayed on a LED array or a LCD screen to induce user's visual evoked potentials (VEPs). User can generate desired commands one after one while he/she stares at target stimulus. Since VEPs are time-locked and phase-locked to the flash onsets of visual stimuli, VEPs induced by gazed targets, having greater amplitudes due to cortical magnification, can be extracted using a simple averaging process to remove task-unrelated noise. The commands corresponding to the detected gazed targets are then identified for paralyzed patients to communicate with external environments. The present VEPbased BCI systems establish a reliable communication channel for users to control environmental devices via their brain waves.