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Sains Malaysiana 48(6)(2019): 1201–1207
http://dx.doi.org/10.17576/jsm-2019-4806-07
Characterization of
Graphene based Capacitive Microphone
(Pencirian Grafen berasaskan
Mikrofon Sentuh Berkapasitor)
HASLINAWATI MOHD MUSTAPHA1, M.F. MOHD RAZIP WEE1, AHMAD RIFQI MD ZAIN1,2 & MOHD AMBRI MOHAMED1*
1Institute
of Microengineering and Nanoelectronic, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia
2Harvard
John A Paulson, School of Engineering and Applied Science, Harvard University,
Cambridge, MA,
United States of America
Diserahkan:
25 Ogos 2018/Diterima: 15 Januari 2019
ABSTRACT
This research focuses
on the design, fabrication and characterization of the graphene based
capacitive microphone. Finite element analysis (FEA)
is first simulated in order to design and study the proposed graphene based
capacitive microphone. While the fabrication introduced MEMS technique
in order to reduce the physical size, volume and cost without neglecting the
performance. This study discusses on physical characteristics of graphene
diaphragm for capacitive microphone. The fabrication of 200 nm air gap and the
free-standing suspended graphene with the contribution of the van der Waals
force between the graphene layer as a diaphragm and the substrate are presented
in this study. The first stage involved in this study was the photolithography
process of patterning electrodes with 4 different dimensions of diaphragm. The
characterization was performed by using surface profilometer, optical
microscopy, Raman spectroscopy and FESEM to evaluate the physical
characteristics of the diaphragm. In the last stage, LCR meter
was used to measure the capacitive change with different diameter of graphene
diaphragm within frequency range of 20 Hz to 20 kHz. FEA analysis
showed the good sensitivity against the frequency response for the largest
proposed diameter of diaphragm.
Keywords: Capacitive
microphone; frequency range; graphene diaphragm; MEMS
ABSTRAK
Kajian ini memberi
tumpuan kepada reka bentuk, fabrikasi
dan pencirian
mikrofon kapasitif berasaskan grafen. Pada permulaan, FEA disimulasikan untuk mereka bentuk dan
mengkaji mikrofon
kapasitif berasaskan grafen. Manakala fabrikasi ini memperkenalkan
teknik MEMS untuk
mengurangkan ukuran
fizikal, isi padu
dan kos
tanpa mengabaikan
prestasi. Kajian ini membincangkan
ciri fizikal
diafragma grafen untuk mikrofon kapasitif. Kami membentangkan
fabrikasi lubang udara sebanyak 200 nm dan grafen tergantung
bebas dengan
sumbangan kekuatan daya Van Der Waals antara lapisan grafen sebagai diafragma dan substrat. Tahap pertama
akan melibatkan
proses fotolitografi elektrod dengan 4 dimensi berlainan diameter diafragma.
Penciriannya dilakukan oleh permukaan profilometer, mikroskop optik, spektroskopi Raman dan FESEM untuk
menilai ciri-ciri diafragma. Di peringkat terakhir, meter LCR digunakan
untuk mengukur
perubahan kapasitif dengan diameter diafragma grafen yang berbeza dengan julat frekuensi
20 Hz hingga 20 kHz. Analisis
FEA
menunjukkan sensitiviti
yang baik terhadap
tindak balas frekuensi
bagi diameter yang paling besar.
Kata kunci: Grafen diafragma; julat frekuensi; kapasitif mikrofon;
MEMS RUJUKAN
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*Pengarang untuk surat-menyurat;
email: ambri@ukm.edu.my
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