The 4th China-American Frontiers of Engineering Symposium Micro/nano and precision manufacturing technologies and applications Dazhi Wang School of Mechanical Engineering Dalian University of Technology 2015. 06. 01 Irvine, US Contact: d.wang@dlut.edu.cn
Outline Research background Research challenges Research progress Cross-scale manufacturing technology E-Jet micro/nano print-patterningpatterning Ultra precision grinding and chemical mechanical polishing technologies
Research background Made in China 2025 Premier Li Keqiang advanced the "Made in China 2025" concept in his Government Work Report. The major areas include: Biomedicine and high-performance medical apparatus Information technology Aerospace and aviation equipment Advanced rail equipment.. Manufacturing of high-performance parts and devices play an important role.
Research challenges of high-performance parts and devices The size has been decreased to micro- and nano-scale. The shape and structure become more complex and precise. The machining accuracy has been improved continuously. The material scope has been increased continuously. Microfluidic chips Flexible electronics Silicon wafer Grephene sensor It is difficult to satisfy the requirements of these parts and devices using conventional manufacturing technologies.
Research progress Cross-scale manufacturing technology E-Jet micro/nano print-patterning Ultra precision i grinding and chemical mechanical polishing technologies
Cross-scale manufacturing technology Microfluidic chips have broad application prospects in rapid diagnosis of major diseases and personalized medicine. Micro-nano cross-scale structure and nano-structure are needed for special function such as filtering, block flowing. Microfluidic chips for diagnosis of myocardial infarction Genome mapping on nanofluidic chips (Nature Biotechnology, 2012) Key difficulties Controllable manufacturing of micro-nano cross-scale structure and special area nano-structure.
Cross-scale manufacturing technology A composited fabrication method based on plasma etching and nanoparticle assembly was proposed. Microchannel, nanochannel and modified biological sample were integrated fabricated. A high quality nanofluidic sensing of biotin was achieved, the concentration of 1 am can be detected. Fabrication of nanochannels and Ag microelectrodes Layout of the NPC-based nanofluidic biosensor Micro- and nanochannel and test result Biosensors and Bioelectronic, 2015
Cross-scale manufacturing technology An integration of hot embossing and inverse UV photolithography is developed to fabricate micro and nanochannels. A complete SU-8 nanofluidic chip was fabricated with a replication precision of 99.5%. Process flow of the 2D nano-mold fabrication SU-8 micro and nanochannels fabrication 130 nm wide, 150 nm high, 4 mm long 2D silicon nano-mold The thermally bonded nanochannels Lab on a chip, 2014
Cross-scale manufacturing technology A controllable fabrication of nanopores based on photopolymerization was proposed. Microfluidic idi chips with highh density nanopore array at specific area was realized. Glass micro-nanofluidic chips integrated with nano gel structure Photosensitive polymerization based on AC Impedance of Enrichment ratio of an inverted fluorescent microscope different nanopores fluorescence ions is 600 Applied Physics Letters, 2014
Cross-scale manufacturing technology Disease diagnosis microfluidic chips Cooperated with CapitalBio Corporation, detection of respiratory tract bacteria. Simultaneously detect 13 kinds of bacteria, detecting time reduced from 2 days to 3 hours, it is in clinical test now. 24-channel radial microchip Isothermal amplification & real-time fluorescent detector
E-Jet micro/nano print-patterning Multi-layer composite element commonly exists in MEMS devices, which are widely used in energy, information, medical treatment, etc. The performance of multi-layer composite MEMS devices was determined by their material composition and microstructure. Controllable fabrication of material and structural composited Key difficulties Controllable fabrication of material and structural composited fabrication.
E-Jet micro/nano print-patterning Print-patterning is an effective way to obtain the material and structural composited fabrication. Print-patterning is an additive manufacturing method and has the advantages of no mask, non-contact, no pressure and low cost. Flowing deformation Droplet flying Pattern Substrate Jetting Flying Deposition Solidification Print-patterning process Patterning MEMS devices
E-Jet micro/nano print-patterning Electrohydrodynamic effect was used to develop a new print-patterning tt i technology. Electrohydrodynamic jet (E-Jet) print- patterning makes use of electrical and mechanical forces to form a fine liquid jet and droplets. Needle Ink Substrate Jet Movement stage E-Jet print-patterning Phenomenon of electrohydrodynamic effect
E-Jet micro/nano print-patterning Advantages of E-Jet print-patterning High resolution Low requirement of needle and ink Strong controllability Suitable for different substrates Droplet diameter can be at nano-scale Droplet size is much smaller than needle Composite film deposition size: less than 1/100 Droplets are charged Non-contact patterning Mi / t t Micro/nano structure direct writing
E-Jet micro/nano print-patterning A layer-by-layer nano structure deposition method based on E- Jet was proposed. Material and structural composited fabrication with nano-scale layers were achieved. E-Jet deposition process 1 0.8 预测值实验值 Modeling of E-Jet deposition 孔隙隙率 0.6 0.4 0.2 ϕ Q P 1 α V f T L 1 ( H) f ( H) W 0 2 4 6 8 沉积高度 (10-3 m) Porosity prediction equation Deposition of catalyst layers with different porosity
E-Jet micro/nano print-patterning Template-assisted E-Jet deposition method combined with embossing sacrificial layer technology was developed. Complex microstructures with high side wall angle and high aspect ratio were achieved. Template-assisted assisted E-Jet Patterned PZT thick film deposition process Patterned graphene structures structures J. Eur. Ceram. Soc., 2012
E-Jet micro/nano print-patterning A point focus electrode was used in E-Jet printing, which enabled the printing of structure in micro-scale resolution. 200μm E-Jet printing Point focusing electrode E-Jet print-patterning equipment E-Jet printed graphene structures E-Jet printed PZT structures Rev. Sci. Instrum., 2013, J. Eur. Ceram. Soc., 2015
E-Jet micro/nano print-patterning Micro fuel cell: integrated MEA An integrated MEA was developed, the common delamination problem was solved, and the reliability of the device was improved. The catalyst layer with material and structure gradient variation was developed, the catalyst utilization was improved. arization / V IR corrected anode pola 0.4 0.3 0.2 MEA1 MEA2 MEA3 0.0 0.1 0.2 0.3 Current density / A cm -2 Gas-liquid two-phase model Mass transferring process Modeling of cell performance Voltage (V) 0.7 0.6 0.5 0.4 0.3 0.2 0.1 MEA-1 MEA-2 MEA-3 80 70 60 50 40 30 20 10 Power density (mw cm -2 ) Integrated MEA after life test Structure of integrated MEA 0.0 0 0 50 100 150 200 250 300 Current density (ma cm -2 ) Cell performance test J. Power Sources, 2013, Fuel cells, 2014
E-Jet micro/nano print-patterning High frequency ultrasonic transducer Annular array high frequency piezoelectric ultrasonic transducer was designed and developed, which achieved a working frequency of 70 MHz. Annular array high frequency ultrasonic transducers Measurement of high frequency ultrasonic transducers piezoelectric micro transformer Measurement of transformer Sens. Actuator A-Phys. 2014
Ultra precision grinding and chemical mechanical polishing technologies Ultra precision grinding and chemical mechanical polishing technologies are widely used for obtaining ultra flat and ultra smooth surface, such as blank wafer flattening, wafer back thinning. Blank wafer flattening Wafer back thinning Key difficulties large size, nano-scale flatness, sub-nm roughness, low residual stresses and damage-free.
Ultra precision grinding and chemical mechanical polishing technologies A new ultra precision and low damage grinding g technology with soft abrasive grinding wheel was developed. Ultra smooth and low damage ground surface wafer was produced. Grinding mechanism Developed SAGW of SAGW Damage depth 170nm Ra= 3.8nm The wafer ground with diamond grinding wheel Damage depth 10nm Ra= 0.7nm The wafer ground with SAGW
Ultra precision grinding and chemical mechanical polishing technologies A full-automatic grinder was developed for 300 mm wafer. A ultra precision wafer grinding-polishing machine was developed. The first automatic ultra precision grinding machine for 300 mm wafer grinding in China Principle and process of back thinning integrated grinding and polishing for wafer with outer rim Silicon wafer Sapphire wafer SiC window Optical window Ultra precision wafer grinding-polishing machine (2-spindle, 2-worktable ) Comparison of thinned wafer with and without outer rim Thinned wafer thickness<50μm,ra<5nm
Ultra precision grinding and chemical mechanical polishing technologies KDP is soft-brittle, temperature sensitive, dissolved in water, which is a difficult-to-machine materials. Abrasive-free polishing slurry with water molecular cluster was developed. Ultra smooth and damage-free surface was obtained using micro water-dissolution and mechanical action of polishing pad. Watercluster brocken pad Natural dissolution Water cluster KDP slurry Developed polishing slurry Water-dissolution polishing surface
Summary Micro-nano cross-scale manufacturing technologies were introduced, microfluidic chips for disease diagnosis and biosensing were produced. E-Jet micro/nano print-patterning technique and equipment were developed, which enables the material and structural composited manufacturing at micro/nano scale. Ultra precision grinding and chemical mechanical polishing technologies were introduced, d ultra smooth and low damage surface wafer was produced.
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