{"title":"Droplet dispensing and splitting by electrowetting on dielectric digital microfluidics","authors":"N. Y. Jagath B. Nikapitiya, S. M. You, H. Moon","doi":"10.1109/MEMSYS.2014.6765801","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765801","url":null,"abstract":"The present study investigates two essential capabilities of electrowetting on dielectric digital microfluidics - 1) high precision and consistency in volume of a unit nanodrop dispensed from a reservoir, and 2) reduction of time to dispense and split drops. These capabilities are sought in applications that need tiny but accurate volume of liquid delivery at high flow rate. For this purpose, we mainly focused on geometry of electrodes and developed novel shapes and arrangements of electrodes in electrowetting on dielectric microfluidic device. To dispense liquid droplets in higher volume precision and consistency, a novel reservoir design named TCC reservoir is introduced. To reduce time to dispense a droplet, L-junction is developed. Y-junction is designed to split a droplet into two at the same speed as droplet dispensing speed by the L-junction, and hence increase the number of droplets arrive to the target area (i.e. at high frequency delivery).","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130567779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masato Suzuki, T. Wada, Tomokazu Takahashi, T. Nishida, Y. Yoshikawa, S. Aoyagi
{"title":"Nano-porous SIO2 electret with high surface potential and high thermal resistance","authors":"Masato Suzuki, T. Wada, Tomokazu Takahashi, T. Nishida, Y. Yoshikawa, S. Aoyagi","doi":"10.1109/MEMSYS.2014.6765665","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765665","url":null,"abstract":"This paper proposes a new electret with high surface potential and high thermal resistance, which is made of nano-porous SiO<sub>2</sub>. Electrical charge density in the nano-porous SiO<sub>2</sub> is higher than that in a normal (i.e., nonporous) SiO<sub>2</sub> because there are many voids in the nano-porous SiO<sub>2</sub> and the interface between void and SiO<sub>2</sub> traps electrical charges strongly. Therefore, decrease rate of the trapped charge density in the nano-porous SiO<sub>2</sub> is lower than that of normal SiO<sub>2</sub>. Since SiO<sub>2</sub> is thermally stable, thermal stability of the electrical charge in nano-porous SiO<sub>2</sub> electret is better than that in a polymer electret. Output power generated by vibration energy harvesting using the nano-porous SiO<sub>2</sub> electret is also larger than that using the normal SiO<sub>2</sub> or polymer electret.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122244605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Hall, Luda Wang, J. Bunch, S. Pourkamali, V. Bright
{"title":"Optical control and tuning of thermal-piezoresistive self-sustained oscillators","authors":"H. Hall, Luda Wang, J. Bunch, S. Pourkamali, V. Bright","doi":"10.1109/MEMSYS.2014.6765863","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765863","url":null,"abstract":"The ability to frequency tune and provide on/off control of electrically driven thermal-piezoresistive self-sustained oscillators through the application of HeNe (632 nm wavelength) laser illumination to devices is reported in this work. Photoexcitation of charge carriers is presented as the physical mechanism to control the piezoresistive coefficient and electrical resistivity enabling these abilities. The results are significant in that they offer a novel means to directly control the electronic output of RF oscillators through photonics.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131242669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MEMS vibration electret energy harvester with combined electrodes","authors":"Q. Fu, Yuji Suzuki","doi":"10.1109/MEMSYS.2014.6765663","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765663","url":null,"abstract":"A novel in-plane MEMS electret energy harvester with combined electrodes of overlapping-area-change and gap-closing converters is proposed for large output power both at low and high vibration accelerations. An early prototype has been successfully micro-fabricated with the single layer silicon-on-insulator process. Soft X-ray charging is employed to establish uniform surface potential around 60 V on vertical electrets on the sidewall of the comb fingers. Up to 1.6 μW output power has been obtained, which corresponds to the effectiveness as high as 57%.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134505752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ALD honeycomb plates enabling robust ultrathin MEMS","authors":"K. Davami, Lin Zhao, I. Bargatin","doi":"10.1109/MEMSYS.2014.6765673","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765673","url":null,"abstract":"This paper reports rigid MEMS structures made of ALD films, which had thicknesses as low as 10 nanometers and were patterned in the shape of a 3D honeycomb. Hexagonal honeycomb lattices offer a dramatically higher flexural stiffness compared to that of planar films, allowing us to fabricate large-area suspended devices without significant warping. Both alumina (Al2O3) and silica (SiO2) structures were fabricated, each presenting a different set of fabrication challenges. The spring constants of the cantilever structures were measured and compared with the simulation results.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133308681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongjoo Kwon, Yoonsun Choi, Kyuhwan Choi, Y. Kim, Seungyul Choi, Junghoon Lee, Jung-mok Bae
{"title":"Development of micro variable optics array","authors":"Yongjoo Kwon, Yoonsun Choi, Kyuhwan Choi, Y. Kim, Seungyul Choi, Junghoon Lee, Jung-mok Bae","doi":"10.1109/MEMSYS.2014.6765576","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765576","url":null,"abstract":"This research is on the development of a micro variable optics array which employs electrowetting as the working principle. The single pixel of the array has four separated electrodes and each of them is controlled independently giving the device multi-degree of freedom. The separated electrodes are fabricated using a thick photoresist and electroplating. Several formulas showing the relation among the radius of curvature, the prism angle, and electrowetting parameters are provided. The prism angles are measured to be ±30° and compared to the calculated values. The measurement of the radius of curvature is also presented showing that the various radiuses of curvature are achievable from concave to convex.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"143 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116047869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Flexible MEA for adult zebrafish ECG recording covering both ventricle and atrium","authors":"Xiaoxiao Zhang, Joyce Tai, Jungwoo Park, Y. Tai","doi":"10.1109/MEMSYS.2014.6765772","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765772","url":null,"abstract":"This paper presents a flexible parylene micro-electrode-array (MEA) that records Electrocardiograms (ECG) from the Zebrafish heart in-vivo, covering both the ventricle and atrium area. ECG is a powerful tool for monitoring the heart activity. While ECG technology for human has been well established, this is not true for zebrafish. Our previous work demonstrated baseline ECG recording from zebrafish using MEMS MEAs [1, 2]. However, due to the body structure and small size of the zebrafish (e.g., the heart is roughly 1mm in size and its atrium is buried deep in the thoracic cavity, Fig.1b.), all zebrafish ECGs to date were only recorded from the ventricular side, making it easy to miss important electrophysiological signals from the atrium. To our knowledge, ECG from the atrial angles in Zebrafish has not yet been demonstrated. This work describes a flexible MEA implant (i.e., specially designed according to zebrafish heart anatomy) that records from both the ventricular and the atrial angles. Furthermore, to demonstrate that this device is useful for heart regeneration monitoring, our work also includes ECG recording before and after laser damage on the ventricle (532nm green light, 32mJ/mm2, 20mJ total). This chosen energy level of laser pulse is first calibrated using ablated heart histology by EthD-1 florescence staining. The post injury ECG data clearly show ST-wave depression, an indication of ventricular abnormal repolarization state. In addition, repeated missing T-wave is observed from the channels recorded from the atrial angles, which indicate abnormalities in atrial physiology. A hypothesis is that since absorption coefficient of 532nm light in body tissue is rather low, the laser beam penetrated deeply in the heart and created damage deep in the atrium as well as the ventricle. The MEA presented here shows potential for an effective tool to study long-term adult zebrafish heart development and regeneration.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128293432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Apparent size correlation: A simple method to determine vertical positions of particles using conventional microscopy","authors":"Michael H. Winer, A. Ahmadi, K. Cheung","doi":"10.1109/MEMSYS.2014.6765797","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765797","url":null,"abstract":"This paper reports a simple and widely applicable particle tracking technique using conventional fluorescence microscopy to determine vertical positions of particles suspended in a fluid. Previous experimental work in this area has been restricted to two-dimensional intensity profiles or confocal and stereoscopic setups for three-dimensional tracking. Using a calibration-based defocusing method, our technique has been experimentally verified and compared with previously observed trends in inertial flow focusing. The technique has proven to be a simple and valuable tool for determining locations of micron-sized particles in microscale flows.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128559994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tuning of nonlinearities and quality factor in a mode-matched gyroscope","authors":"E. Tatar, T. Mukherjee, G. Fedder","doi":"10.1109/MEMSYS.2014.6765762","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765762","url":null,"abstract":"This paper examines methods to electrically tune quality factor (Q) and cubic softening nonlinearity of a mode-matched MEMS gyroscope. The gyroscope includes traditional drive-sense combs and dedicated shaped combs for cubic nonlinearity and frequency tuning. In addition to nonlinearity, Q can be tuned by understanding the nature of the losses. Interconnect resistances are added to the electromechanical resonator model to capture the electrical losses that depend on the applied DC proof mass potential.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"2014 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128700918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Transition of Q-dot distribution on microtubule array enclosed by PDMS sealing for axonal transport model","authors":"K. Fujimoto, H. Shintaku, H. Kotera, R. Yokokawa","doi":"10.1109/MEMSYS.2014.6765839","DOIUrl":"https://doi.org/10.1109/MEMSYS.2014.6765839","url":null,"abstract":"In this paper, we show a reconstruction of kinesin driven transport system in three dimensionally (3D) enclosed channels whose scale is similar to axons. Our experimental method enabled successful motility of a large number of kinesin-labeled Q-dots on microtubules (MTs) in enclosed channels. To control the direction of kinesin motility, we prepared a polarity-defined MT array in channels. Due to the directional motility of kinesin, time evolutional accumulation of transported Q-dot at one end of enclosed channels, where corresponds to microtubule (MT) plus end, was observed. This is the first step for an in vitro model of motor protein-based active transport with a 3D spatial confinement mimicking intracellular environment, which is applicable to analyze a regulation mechanism of intracellular transport.","PeriodicalId":312056,"journal":{"name":"2014 IEEE 27th International Conference on Micro Electro Mechanical Systems (MEMS)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133919318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}