Fabrication of a zirconia MEMS-based microthruster by gel casting on PDMS soft molds

Abstract

A zirconia microelectromechanical-system-based microthruster was fabricated through a newly developed fabrication route. Gel casting of homogenously dispersed zirconia suspension on polydimethylsiloxane soft mold was utilized to replicate the geometries of microthruster design onto a ceramic layer of about 1.2 mm thick. Lamination of the patterned ceramic layer to another flat ceramic layer and subsequent sintering produced the microthruster. Characterizations on the fabricated prototype showed good shape retention on the replicated geometries and good quality of lamination. Shrinkage of about 10-15% was noted after sintering. The current fabrication route is particularly promising for the development of high-performance micropropulsion systems which require their structural material to survive in an extreme environment which is corrosive, of high temperature and highly oxidative.

Fabrication of Embedded Microstructures Via Lamination of Thick Gel‐Casted Ceramic Layers

“…The optimized composition of ceramic suspension for gel casting is summarized in Table . For gel casting of yttria‐stabilized zirconia (YSZ) ceramic layers, the experimental procedures and sintering process are explained in detail in authors' previous work …”

“…For gel casting of yttria-stabilized zirconia (YSZ) ceramic layers, the experimental procedures and sintering process are explained in detail in authors' previous work. 21 Before casting onto the PDMS soft molds, initiator (ammonium persulphate, Merck, Whitehouse Station, NJ) and catalyst (N, N, N′, N′-tetramethyl ethylenediamine, Merck) were added at 2 and 1 lL/g of suspension, respectively, to initiate the polymerization. Further heating on the casted suspension at 50°C in oven accelerates the polymerization process to complete in 2 h. The heating temperature was then increased to 80°C for one hour for complete drying.…”

Femtosecond laser micromachining of zirconia green bodies

“…Recently, microscale parts such as micro electro mechanical components, biosensors and microfluidic components, have been fabricated using zirconia for various purposes (Barsch et al, 2009;Çetinel and Bauer, 2013;Cheah et al, 2012;Denry and Kelly, 2008;Rajabi et al, 2015). Microscale components often have microholes and microchannels as small as several micrometers in size.…”

Thermal Flow Sensors for Harsh Environments

“…Despite being not abundant, processing techniques for this material were well established. Zirconia based micro-thruster device with integrated calorimetric flow sensor was developed by Cheah et al for the use in spacecraft[81].…”