{"title":"Dielectric constant enhancement of BaTiO3/SU-8 for low-voltage droplet actuation","authors":"","doi":"10.1016/j.sna.2024.115919","DOIUrl":null,"url":null,"abstract":"<div><div>Digital microfluidics (DMF) technology, which called lab-on-a-chip will bring technological innovations to the field of biochemistry. Electro-wetting-on-dielectric (EWOD) is one of the forms of DMF which actuate independent droplets through electric field enabling more accurate and efficient actuation. Nowadays, the high driving voltage required for droplet actuation remains a major obstacle to the practical application of this technology. Dielectric layer is the main factor affecting the driving voltage. In this study, we fabricate a dielectric layer film that can reduce the driving voltage by doping BaTiO<sub>3</sub> nanoparticles with high dielectric constant in SU-8 at room temperature. The volume ratio of dopant particles and spin coating speed are studied to determine the optimal processing conditions for low-voltage droplet actuation. As the volume ratio of the dopant particles increased, the dielectric layer dielectric constant firstly increases and then decreases. When the volume ratio of BaTiO<sub>3</sub>:SU-8 is 1:10, the maximum dielectric constant is achieved. The dielectric wetting properties follow the same trend as the change in dielectric layer dielectric constant. Thus, the parameters of a volume ratio of 1:10 and spin coating speed of 7500 rad/min are finally selected for the preparation of the dielectric layer. These measures resulted in lower threshold voltages for droplet actuation, which contributes to advancing the application and widespread adoption of DMF technology.</div></div>","PeriodicalId":21689,"journal":{"name":"Sensors and Actuators A-physical","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sensors and Actuators A-physical","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0924424724009130","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Digital microfluidics (DMF) technology, which called lab-on-a-chip will bring technological innovations to the field of biochemistry. Electro-wetting-on-dielectric (EWOD) is one of the forms of DMF which actuate independent droplets through electric field enabling more accurate and efficient actuation. Nowadays, the high driving voltage required for droplet actuation remains a major obstacle to the practical application of this technology. Dielectric layer is the main factor affecting the driving voltage. In this study, we fabricate a dielectric layer film that can reduce the driving voltage by doping BaTiO3 nanoparticles with high dielectric constant in SU-8 at room temperature. The volume ratio of dopant particles and spin coating speed are studied to determine the optimal processing conditions for low-voltage droplet actuation. As the volume ratio of the dopant particles increased, the dielectric layer dielectric constant firstly increases and then decreases. When the volume ratio of BaTiO3:SU-8 is 1:10, the maximum dielectric constant is achieved. The dielectric wetting properties follow the same trend as the change in dielectric layer dielectric constant. Thus, the parameters of a volume ratio of 1:10 and spin coating speed of 7500 rad/min are finally selected for the preparation of the dielectric layer. These measures resulted in lower threshold voltages for droplet actuation, which contributes to advancing the application and widespread adoption of DMF technology.
期刊介绍:
Sensors and Actuators A: Physical brings together multidisciplinary interests in one journal entirely devoted to disseminating information on all aspects of research and development of solid-state devices for transducing physical signals. Sensors and Actuators A: Physical regularly publishes original papers, letters to the Editors and from time to time invited review articles within the following device areas:
• Fundamentals and Physics, such as: classification of effects, physical effects, measurement theory, modelling of sensors, measurement standards, measurement errors, units and constants, time and frequency measurement. Modeling papers should bring new modeling techniques to the field and be supported by experimental results.
• Materials and their Processing, such as: piezoelectric materials, polymers, metal oxides, III-V and II-VI semiconductors, thick and thin films, optical glass fibres, amorphous, polycrystalline and monocrystalline silicon.
• Optoelectronic sensors, such as: photovoltaic diodes, photoconductors, photodiodes, phototransistors, positron-sensitive photodetectors, optoisolators, photodiode arrays, charge-coupled devices, light-emitting diodes, injection lasers and liquid-crystal displays.
• Mechanical sensors, such as: metallic, thin-film and semiconductor strain gauges, diffused silicon pressure sensors, silicon accelerometers, solid-state displacement transducers, piezo junction devices, piezoelectric field-effect transducers (PiFETs), tunnel-diode strain sensors, surface acoustic wave devices, silicon micromechanical switches, solid-state flow meters and electronic flow controllers.
Etc...