Fabrication and Characterization of Glassy Carbon MEMS

Abstract

This paper describes the fabrication of free-standing high-carbon microstructures by softlithographic techniques; these structures ranged in complexity from simple beams to complex, suspended deflectors. Microstructures of polymeric precursors (copolymers of furfuryl alcohol-phenol) to high-carbon solids were fabricated using poly(dimethylsiloxane) (PDMS) molds. Carbonization of these microstructures under argon resulted in mass loss (up to 45%) and shrinkage (up to 20% linearly); the density increased to reach a plateau value of ∼1.5 g/cm 3 at ∼900 °C. Microstructures pyrolyzed at 900 °C were electrically conductive, with a conductivity of ∼10 -2 Ω cm. Elementary microelectromechanical functions were demonstrated in these microstructures: electrostatic actuation induced deflection or vibrations of suspended structures. The measurement of the frequency of resonance of highcarbon cantilevered beams allowed the determination of Young's modulus for the solid: typical values were ∼15-20 GPa. The microelectromechanical properties of more complex structures (microresonators, light deflectors) were also determined. This paper demonstrates that high-carbon microstructures can be easily fabricated that have potential use as the active components of MEMS.

3D Carbon Scaffolds for Neural Stem Cell Culture and Magnetic Resonance Imaging

“…[12,13] One very attractive yet rather unexplored feature of glassy carbon is its excellent cytocompatibility, [14][15][16][17][18] which, in combination with its mechanical strength, [9] inertness, and patternability, [10] makes it a very suitable material for the fabrication of 3D cell culture platforms. …”

“…While not always an issue, in cases of extended culture times, cell cultures require a scaffold that will maintain its mechanical integrity. In this work, we propose glassy carbon as a material capable of overcoming these challenges.Conversion of polymer structures into glassy carbon using pyrolysis is a widespread process that is extensively used for the fabrication of carbon MEMS and NEMS, [9,10] battery and supercapacitor anodes, [11] and carbon nanofibers. [12,13] One very attractive yet rather unexplored feature of glassy carbon is its excellent cytocompatibility, [14][15][16][17][18] which, in combination with its mechanical strength, [9] inertness, and patternability, [10] makes it a very suitable material for the fabrication of 3D cell culture platforms.…”

Зависимость Механических Свойств Сорбентов От Размеров Нанопор

“…Получение ПУМ с размерами пор от микро-до нанопор в зависимости от температуры, при которой осуществляется испарение полифурфурилового спирта, реализуется в процессе пиролиза [15][16][17].…”

“…В [14] экспериментально и теоретически по-казано, что модуль Юнга стеклоуглерода с плотно-стью 1.4 g/сm 3 составляет 30 GPa при размере нанопор 15−20 nm. При этом в [15][16][17] показано, что в процессе пиролиза можно управлять размерами пор стеклоуг-лерода. В связи с этим в настоящей работе впервые проведено теоретическое исследование изменения мо-дуля Юнга ПУМ плотностью 1.4 g/сm 3 в зависимости от размера пор.…”

Microfabrication, Microstructures and Microsystems

“…MIMIC, pTM and replica molding have been used to fabricate microstructures of a wide range of materials, including polymers, inorganic and organic salts, sol-gels, polymer beads and precursor polymers to ceramics and carbon. The feasibility of these molding techniques has been demonstrated by the fabrication of chirped, blazed diffraction gratings [60], polymeric waveguides [121], waveguide interferometers/couplers ltZZl, interdigitated carbon capacitors [118], and suspended carbon microresonators [123). Without steps for transferring patterns, photolithography can only be used to generate microstructures in the classes of polymers that have been developed as photoresists.…”