Implementation of electrostatically controlled Fabry-Perot interferometer using nanoporous anodic aluminum oxide layer

Abstract

This study presents the use of nanoporous anodic aluminum oxide (np-AAO) for Fabry-Perot interferometer (FPI). The merits of this np-AAO Fabry-Perot interferometer are as follows, (1) in-use stiction of the actuation np-AAO membrane can be reduced by the nanoporous textures, (2) dielectric charging can be largely reduced by np-AAO material in this study, thus the offset voltage of the polarities close to zero and hysteresis curves are symmetric [1], (3) driving (pull-in) voltage can be reduced due to superior dielectric constant (ε=7.05) of np-AAO [2], and (4) in addition, refractive index can be adjusted by pore size [3]. The tests demonstrate the performance of presented Fabry-Perot interferometer.

The influence of the morphological characteristics of nanoporous anodic aluminium oxide (AAO) structures on capacitive touch sensor performance: a biological application

“…For example, considering the measured capacitance for sample P1 and applying eqn (4) , the dielectric constant ( ε AAO ) can be estimated to be 8.69, which is close to the values typically reported in literature. 38,39 In this work, the sensitivity, S , of the AAO-based capacitive touch sensors in contact with the metal Al circular disk was determined using eqn (5) 40 where Δ C % = [( C − C 0 )/ C 0 ] × 100 is the percentage change in capacitance of the sensor in which C corresponds to the capacitance value of the AAO sensor in contact with the metal Al circular disk, C 0 is the initial capacitance of the AAO sensor (with open pores but not covered by the metal Al circular disk) and A is the top sensing electrode area fully contacted with the Al conductor circular disk of 7.5 mm in diameter. From Fig.…”

“…For example, considering the measured capacitance for sample P1 and applying eqn (4), the dielectric constant (3 AAO ) can be estimated to be 8.69, which is close to the values typically reported in literature. 38,39 In this work, the sensitivity, S, of the AAO-based capacitive touch sensors in contact with the metal Al circular disk was determined using eqn (5) 40…”

Nanoporous anodic aluminum oxide as a promising material for the electrostatically-controlled thin film interference filter

“…The aforementioned design considerations for the MEMS optical filter can be improved by selecting the proper thin film materials utilizing simple microfabrication processes. Thus, the currentt study extends the concept in [15,16] to the design and implementation of the bi-stable MEMS optical filter using the transparent nanoporous anodic aluminum oxide (np-AAO) film. The np-AAO film is a promising material and has found many current applications [17][18][19][20][21].…”

“…The np-AAO film is a promising material and has found many current applications [17][18][19][20][21]. As reported in [15,16], the np-AAO with hexagonally arranged nanopores is exploited to act as a template to implement 1D nanostructured materials including nanopillars, nanowires and nanodot arrays. The optical filters to control the interferometric property, by adjusting the pore size of np-AAO, are reported in [15,22].…”

“…In this study, the proposed bi-stable optical filter consisting of np-AAO film is driven by the electrostatic force. The driving voltage of the proposed MEMS optical filter is reduced by the high dielectric constant of np-AAO film [16]. In addition, the np-AAO film with nanoporous texture is arranged as the contact interface to reduce the contact area.…”