Design and Modeling of a Nanomechanical Sensor Using Silicon Photonic Crystals

Abstract

Abstract-Conventionally a line defect in the photonic crystal (PhC) is used to create a waveguide for light propagation through the PhC. A PhC based filter is designed by introducing micro-cavities within the line defect so as to form the resonant bandgap structure for PhC. Such a PhC waveguide (PhCWG) filter shows sharp resonant peak in output wavelength spectrum. We proposed a suspended silicon bridge structure comprising this PhCWG filter structure. Since the output resonant wavelength is sensitive to the shape of air holes and defect length of the micro-cavity. Shift of the output resonant wavelength is observed for suspended PhCWG beam structure under particular force loading. In other words, the induced strain modifies the shape of air holes and the spacing among them. Such an effect leads to shift of resonant wavelength. Under optical detection limitation of 0.1 nm for resonant wavelength shift, the sensing capability of this nanomechanical sensor is derived as that vertical deformation is 20-25 nm at the center and the smallest strain is 0.005% for defect length. This innovative design conceptualizes a new application area for PhCs, i.e., the nanometer-scale physical sensors for strains and forces. Index Terms-Microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS), nanomechanical sensor, nanophotonics, photonic crystals (PhCs).

A review for optical sensors based on photonic crystal cavities

“…Considering the effective action area of the applied pressure was equal to 1 mm 2 , the detection limit of about 0.3 mN could be obtained. Then, C. Lee et al demonstrated that the shoulder-coupled PCC in a suspended silicon bridge structure could also be used for pressure measurement [77]. As shown in Fig.…”

“…11 (a) Structure of H0 slot cavity for displacement sensing [77] and (b) structure of PCC integrated with cantilever for stress sensing [78] .…”

“…As a result, the resonant conditions (such as shape of A c c e p t e d M a n u s c r i p t resonant spectrum, Q factor, and transmittance) of PCC will be changed, which will influence the sensing properties (sensitivity, linearity, detection limit, stability, sensing range, etc.) of the mechanical sensor and even cause the sensor unable to work [77]. To resolve this problem, in 2013, D. Yang et al proposed a torsion-free pressure sensor based on a piston-typed H0 cavity structure, as shown in Fig.…”

Biomedical applications of nanobiosensors: the state-of-the-art

“…Microcantilevers, such as those used in atomic force microscopes, have been recently employed as this new class of biosensors. 43 Nanomechanical biosensors have demonstrated that they are capable of detecting single base mismatches in oligonucleotide hybridization without labeling, 44,45 as well as performing protein recognition 46 with extreme sensitivity. Other DNA detection schemes have been reported, for example, one which is used as a capture oligonucleotide combined with a DNA probe attached to a gold nanoparticle.…”

Computational Study of Photonic Crystals Nano-Ring Resonator for Biochemical Sensing

“…First of all, PC resonator sensors are integrated in microbeams and microcantilevers for force and mechanical strain detection [12]- [14]. Secondly the resonant wavelength of PCs resonator sensors are extremely sensitive to a small refractive index change attributed to medium around hole surface.…”