title: A tapered aluminium microelectrode array for improvement of dielectrophoresis-based particle manipulation.
abstract: In this work, the dielectrophoretic force (F(DEP)) response of Aluminium Microelectrode Arrays with tapered profile is investigated through experimental measurements and numerical simulations. A standard CMOS processing technique with a step for the formation of a tapered profile resist is implemented in the fabrication of Tapered Aluminium Microelectrode Arrays (TAMA). The F(DEP) is investigated through analysis of the Clausius-Mossotti factor (CMF) and cross-over frequency (f(xo)). The performance of TAMA with various side wall angles is compared to that of microelectrodes with a straight cut sidewall profile over a wide range of frequencies through FEM numerical simulations. Additionally, electric field measurement (EFM) is performed through scanning probe microscopy (SPM) in order to obtain the region of force focus in both platforms. Results showed that the tapered profile microelectrodes with angles between 60° and 70° produce the highest electric field gradient on the particles. Also, the region of the strongest electric field in TAMA is located at the bottom and top edge of microelectrode while the strongest electric field in microelectrodes with straight cut profile is found at the top corner of the microelectrode. The latter property of microelectrodes improves the probability of capturing/repelling the particles at the microelectrode's side wall.
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. muhdramdzan@ukm.edu.my.
authors.forename: Muhamad Ramdzan
authors.initials: MR
authors.lastname: Buyong
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. farhad@ukm.edu.my.
authors.forename: Farhad
authors.initials: F
authors.lastname: Larki
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. muhammadelfaiz@gmail.com.
authors.forename: Mohd Syafiq
authors.initials: MS
authors.lastname: Faiz
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. azlanhamzah@ukm.edu.my.
authors.forename: Azrul Azlan
authors.initials: AA
authors.lastname: Hamzah
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. jumrilyunas@ukm.edu.my.
authors.forename: Jumrail
authors.initials: J
authors.lastname: Yunas
authors.affiliation: Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, Bangi, Selangor 43600, Malaysia. burhan@vlsi.eng.ukm.my.
authors.forename: Burhanuddin Yeop
authors.initials: BY
authors.lastname: Majlis
keywords: CMOS; array; dielectrophoresis; numerical simulation; taper microelectrode