Fabrication of Tapered Bio Mimetic Cilia Using Bulk Lithography and Ceramic Mold

2014 ◽  
Author(s):  
Chandrashekar V. Adake ◽  
Parag Bhargava ◽  
Prasanna S. Gandhi ◽  
Bhargava Kashyap
Keyword(s):  
Soft Lithography ◽  
Ceramic Body ◽  
Aqueous Suspension ◽  
Slip Casting ◽  
Single Layer ◽  
Ceramic Mold ◽  
Green Body ◽  
Polydimethyl Siloxane ◽  
Casting Technique ◽  
Negative Impression

This paper presents fabrication of tapered, high aspect ratio bio mimetic cilia from Nickel-polydimethyl siloxane (Ni-PDMS) composite by using bulk lithography technique and ceramic molding. Many research groups suggested fabrication of bio mimetic cilia using various techniques which are based on soft lithography and VLSI techniques. Recently a novel single layer micro fabrication technique known as ‘bulk lithography’ which uses an unconstrained photopolymer has been reported by co-authors. This technique is used to fabricate a polymer cilia pattern (an array of photopolymerised inverted cone profile) and using this pattern a ceramic green body is fabricated by slip casting technique. An aqueous suspension containing sub micron size alumina is used to cast ceramic green body. After casting this cilia pattern makes negative impression of tapered holes on green ceramic body. During sintering of green ceramic body the polymer burns off resulting in ceramic mould with tapered holes imprinted on it. This mold retains shape of a tapered hole though it shrinks in size after sintering. This mold is used further to cast Ni-PDMS composite in the form of cilia structures.

Rheological Behavior of Silicon Nitride Whiskers

1992 ◽  
Vol 287 ◽  
Author(s):  
Patricio Toro ◽  
Oscar Wittke
Keyword(s):  
Rheological Behavior ◽  
Carbothermal Reduction ◽  
Ceramic Body ◽  
Flow Behavior ◽  
Aqueous Suspension ◽  
Slip Casting ◽  
Sem Analysis ◽  
Ftir Analysis ◽  
Rice Husks ◽  
X Ray

ABSTRACTSi3N4 whiskers are found through SEM analysis of powder obtained by carbothermal reduction of calcined Chilean rice husks. X-ray and FTIR analysis showed that the ceramic material was mainly α-Si3N4. A stable aqueous suspension with 30 or 40 wt% Si3N4 was obtained at pH = 8.5. A maximum viscosity at pH = 4.0 and low rpm was also observed and this rheological behavior is consistent with the zeta potential data. An irregular flow behavior near pH 4.0 shows a decrease in viscosity that is related to active impurities as detected by potentiometric titrations.These rheological studies conducted allowed production of a Si3N4 green ceramic body measuring 170 × 25 × 5 mm formed by slip casting. The optimal aqueous suspension of powder contained the following: 17.0 g Si3N4, 1.0 g Cu2O, 1.3 g bentonite, and 20.0 g water.

Contact Damage of Curved Multi-Layered Ceramics: Prepared by Slip Casting Technique

2009 ◽  
Vol 417-418 ◽  
pp. 461-464
Author(s):  
Tarek Qasim ◽  
Yeo Khee Wee ◽  
Wei Lun Cai ◽  
Xiao Zhi Hu
Keyword(s):  
Slip Casting ◽  
Single Layer ◽  
Video Camera ◽  
Functionally Graded ◽  
Contact Damage ◽  
Casting Technique ◽  
Failure Patterns ◽  
Failure Evolution ◽  
Final Failure ◽  
Layered Ceramics

Contact damage of curved multi-layered systems, consisting of a brittle zirconia (3Y-TZP)/Alumina (Al2O3) coating – prepared by slip casting – on a compliant polymeric substrate from indentation by a hard tungsten carbide sphere is investigated. The essence of this study is to compare the structural performance of layered ceramics, and monolithic ceramic in the brittle coating and compliant substrate of dental crown-like systems. The specimens are loaded at the axis of symmetry. The failure evolution to initiate cracking and final failure patterns in curved multi-layered specimens are compared to those of the single layer specimens of the same thickness and the same study are conducted again with the flat specimens. The onset of fracture is observed in situ using a video camera. It is demonstrated that in all specimens, cone cracking occurs prior to radial cracking, with the latter being defined as the primary mode of catastrophic failure. The multi-layered ZTA (Zirconia Toughened Alumina) specimens prepared by slip casting possessed a distinct final failure pattern in comparison with a single layer specimen. The results of this study provide useful guidelines for building brittle multi-layered coating systems with the functionally graded feature, and complex shapes with geometrical uniformity.

Electric Discharge Machining of Conducting Ceramics - A Review

2021 ◽  
Vol 1019 ◽  
pp. 121-128
Author(s):  
T. G. Sachidhananda ◽  
V. Adake Chandrashekhar
Keyword(s):  
Electrical Discharge Machining ◽  
Ceramic Body ◽  
Tape Casting ◽  
Slip Casting ◽  
Pyrolytic Carbon ◽  
Machining Processes ◽  
Electric Discharge Machining ◽  
Complex Shapes ◽  
Assisting Electrode ◽  
Machining Characteristics

Electrical Discharge machining (EDM) is a nonconventional machining technique, which has been widely used to produce dies and mold. Harder Materials can be machined into complex shapes as long as they conduct electricity. Recent advances in the technologies brought the development of new engineering materials, which are hard to machine with traditional machining processes. Being one of these materials, ceramics possess some unique properties like piezoelectricity and tribological properties which are not found in metal and polymers. EDM is capable of machining these ceramics, given these materials have an adequately high electrical conductivity. Preparing conducting ceramics is pre-requisite for incorporating ceramics in EDM. Different techniques such as compaction, tape casting, extrusion, injection molding and slip casting are used form green ceramic body. These green bodies are subsequently sintered to obtain ceramic parts. Adding conducting elements in the ceramics while processing results in conducting ceramics. These additions increase hardness but fracture toughness of body is compromised. Ceramic parts can also be machined by using assisting electrode and pyrolytic carbon technique. This paper discusses the various methods of shaping conducting ceramics and its machining characteristics for EDM application

Organic Thin Film Transistors Fabricated by a Solution Process Using Direct Patterned Single-Layer Graphene Electrodes

2020 ◽  
Vol 20 (10) ◽  
pp. 6435-6440
Author(s):  
Do-Kyung Kim ◽  
Jae-Hyung Han ◽  
Muhan Choi. ◽  
Jin-Hyuk Bae
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Soft Lithography ◽  
Solution Process ◽  
Single Layer ◽  
Organic Thin Film Transistors ◽  
Single Layer Graphene ◽  
Metal Catalyst ◽  
Organic Thin Film ◽  
Layer Graphene

We propose the direct transfer method of single-layer graphene (SLG) from metal catalyst Cu-foil to a polymeric insulator and the direct patterning method of the SLG for electrodes of organic thin-film transistors (OTFTs) without contamination using soft-lithography. Through soft-lithography, SLG can be formed in various patterns relatively easily in comparison with the conventional photolithography method that has multiple complex process steps to make graphene patterns. Furthermore, the 6,13-bis(triisopropylsilylethynyl) pentacene OTFTs are fabricated in solution with SLG source and drain electrodes. As a result, the field-effect mobility of OTFTs based on SLG electrodes was enhanced about 4 times in comparison with that of OTFTs using typical metal electrodes due to the decrease in contact resistance.

Optimisation of Performance of Dispersants in Aqueous Titanium Slips

2012 ◽  
Vol 520 ◽  
pp. 330-334 ◽  
Author(s):  
Qian Xu ◽  
Brian Gabbitas ◽  
Steven Matthews ◽  
De Liang Zhang
Keyword(s):  
Large Scale ◽  
Slip Casting ◽  
Streaming Potential ◽  
Casting Technique ◽  
Anionic Polyelectrolyte ◽  
Complex Shapes ◽  
Ti Powder ◽  
Ceramic Casting

Slip casting is a well-established ceramic casting technique used for large scale fabrication of ceramic products with complex shapes. A homogenous slip with a desired level of stability is required, which is controlled using a dispersant. This paper describes the selection and optimisation of various dispersants used to produce Ti powder slips. A consideration of the effect of concentration and pH of the solvent on the dispersion of anionic polyelectrolyte dispersants (Dispex N-40, Synthecol SD375 & Dolapix CE64) was examined by measuring the sedimentation height and rate, the streaming potential and the slip viscosity. It was found that Dolapix CE64 showed the best deflocculating effect at 0.3dw.% with pH of 7. In particular, the measurements on Dolapix CE64 gave consistent results. This indicated that Dolapix CE64 is an effective dispersant in the preparation of a titanium slip.

Microfluidic operations using deformable polymer membranes fabricated by single layer soft lithography

Lab on a Chip ◽  
2005 ◽  
Vol 5 (3) ◽  
pp. 350 ◽  
Author(s):  
Narayan SundararajanAuthors contributed equ ◽  
Dongshin KimCurrent address: Department of B ◽  
Andrew A. Berlin
Keyword(s):  
Soft Lithography ◽  
Polymer Membranes ◽  
Single Layer

scholarly journals Evaluation of filtration efficiency for single layer and double layers alumina filter using aqueous suspension

2010 ◽  
Vol 60 (10) ◽  
pp. 505-510
Author(s):  
Osamu Yamakawa ◽  
Hiroshi Shirakawa ◽  
Osamu Sakurada ◽  
Minoru Hashiba
Keyword(s):  
Aqueous Suspension ◽  
Single Layer ◽  
Filtration Efficiency ◽  
Double Layers

Particle Orientation of Alumina Green Body Made by Slip Casting

2004 ◽  
Vol 264-268 ◽  
pp. 97-100 ◽  
Author(s):  
S. Watanabe ◽  
Satoshi Tanaka ◽  
Nozomu Uchida ◽  
Keizo Uematsu
Keyword(s):  
Slip Casting ◽  
Particle Orientation ◽  
Green Body

Preparation of N-Methylpolyborosilazane -Derived Bulk Si-B-N-C Ceramics by Warm-Pressing and Pressureless Pyrolysis

2012 ◽  
Vol 557-559 ◽  
pp. 1148-1151
Author(s):  
Zhen Quan Liu ◽  
Jing Zhang ◽  
Xian Xing Qiu ◽  
Yu Qing Peng ◽  
Ke Qing Han ◽  
...  
Keyword(s):  
High Temperature ◽  
Ceramic Body ◽  
Thermo Gravimetric Analysis ◽  
Amorphous Structure ◽  
Cross Linking ◽  
Gravimetric Analysis ◽  
Green Body ◽  
Thermo Gravimetric ◽  
Temperature Resistance ◽  
Bulk Ceramic

Additive-free bulk Si-B-N-C ceramics were prepared by pyrolysis of preceramic precursor (PBS-Me), which mainly involves cross linking, warm-pressing and pyrolysis. The density of crack-free bulk ceramic attains 1.94 g/cm3 when Calcined at 1300 °C. The shaped workpieces exhibit amorphous structure even be pyrolysised at 1400°C in N2, and there are some pores existing in the green body derived from warm-pressing and the resulting Si-B-N-C ceramic body, and these pores allow the gaseous byproducts be expeled from bodies. The pyrolyzed samples were studied by high temperature thermo gravimetric analysis, it shows that the Si-B-N-C body had an excellent high temperature resistance.

Integrated Process of Ceramic Slip Using Rotating Technique

2016 ◽  
Vol 1133 ◽  
pp. 161-165 ◽  
Author(s):  
Abdul Rahim Mahamad Sahab ◽  
Nor Hayati Saad ◽  
Farrahshaida M. Salleh ◽  
Azlin Hamidi ◽  
Doll Said Ngah ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Slip Casting ◽  
Conventional Technique ◽  
Ceramic Product ◽  
Advanced Technique ◽  
Moulding Process ◽  
Casting Technique ◽  
Green Strength ◽  
Ceramic Slip ◽  
Test Result

Hollow shape product from ceramic material is produced generally by slip casting technique. This conventional technique is widely used in ceramic industries. Ceramic slip compound by rotating technique namely slip rotary moulding process is studied for producing the hollow shape green ceramic product. From experimental studies this advanced technique has exemplified high potential in producing green hollow shape ceramic product for mass production. Laboratory test result shows that the rotating technique is able to produce hollow shape green ceramic product with desired thickness and sufficient green strength (1 MPa) able to hold during de-moulding process.

Sign in / Sign up

Export Citation Format

Share Document