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We propose a new generalized Su–Schrieffer–Heeger model with hierarchical long-range hopping based on a one-dimensional tetratomic chain. The properties of the topological states and phase transition, which depend on the cointeraction of the intracell and intercell hoppings, are investigated using the phase diagram of the winding number. It is shown that topological states with large positive/negative winding numbers can readily be generated in this system. The properties of the topological states can be verified by the ring-type structures in the trajectory diagram of the complex plane. The topological phase transition is strongly related to the opening (closure) of an energy bandgap at the center (boundaries) of the Brillouin zone. Finally, the non-zero-energy edge states at the ends of the finite system are revealed and matched with the bulk–boundary correspondence. [ABSTRACT FROM AUTHOR]

A new method for prototype of a three dimensional (3 D) microfluidic device on piezoelectric substrate was presented. Wires were stick by colloidal starch, and dried in a thermotank for three dimensional channels mold. The mold was slightly placed in a groove with poly(dimethylsiloxane). After having been solidified, these wires were drawn off to form 3 D microchannels. Surface acoustic wave was used to driven sample droplet to the inlet of the microchannel in microfluidic device. Red fluid transportation in different microchannels was successfully demonstrated using the 3 D microfluidic device at 24.5 dBm signal power for verifying the function of the microfluidic device. [ABSTRACT FROM AUTHOR]

A method for spatial transportation of a droplet was presented. Spatial transporting characteristic was theoretically analyzed. The droplet on an YX-128° LiNbO3 piezoelectric substrate was exerted the acoustic streaming force and resistance from a steel ball with 2 mm diameter, which was fixed on the piezoelectric substrate by help of polydimethylsiloxane (PDMS). The droplet was then transported along the spherical surface. Experimental results show that spatial transportation height is relied on the size of the droplet and the power of an electric signal. 1.5 µl red ink droplet can be transported to the ball top at 30.8 dBm electric signal power. [ABSTRACT FROM AUTHOR]

A method for obtaining temperature characteristics of a water droplet encapsulated by a paraffin oil droplet was presented. An interdigital transducer with 27.5 MHz center frequency was fabricated on a 128°YX-LiNbO3substrate using microelectric technology. A micro temperature sensor was coated by poly (dimethylsilicone) (PDMS) film to improve the adhesiveness to the water droplet, and then fixed by a PDMS block. Purified water droplets encapsulated by paraffin oil droplets were demonstrated. Results show that their temperature cure fell in between that of the pure droplet and that of the pure paraffin oil droplet at the same power of electric signal. [ABSTRACT FROM PUBLISHER]

A new method for heating microfluid in a polydimethylsiloxane (PDMS) array chip is presented. Interdigital transducers are fabricated on a 128° YX-LiNbO3substrate. A 4 × 4 polydimethylsiloxane array chip is placed on the piezoelectric substrate, where a heat transfer pillar with a heat transfer sheet is connected with every reaction zone in the PDMS array chip. An oil droplet is driven for selecting special heat transfer pillar to heat the microfluid in the special reaction zone. Theoretical calculation of heat transfer is finished. At equilibrium state, the emitted energy per second during heat transfer is 7.436 mJ at 30.0 dBm electric signal power. [ABSTRACT FROM AUTHOR]

A new method for fabricating a paper based microfluidic device in a printed circuit board is presented. The printed circuit board is hollowed out to form a pattern of paper channels. When a polydimethylsiloxane (PDMS) film is mounted on the bottom of the PCB, liquid PDMS is filled in the areas having been hollowed out, and solidified in a constant temperature oven. Paper pattern is then mounted on the solidified PDMS, while a piezoelectric device with an interdigital transducer is embedded into the PCB. At last, PDMS film is covered on the surface of paper channels. Microfluidic transportation and color development reaction are demonstrated in presented microfluidic platform. Results show paper channels and the piezoelectric device can be integrated into the printed circuit board, and surface acoustic wave can drive a microfluid to the paper channels for microfluidic analysis. [ABSTRACT FROM PUBLISHER]

A new method for splitting droplets in a channel was presented. Two interdigital transducers were fabricated on a 1280yx-LiNbO3substrate using microelectrical technology. A poly (dimethylsiloxane) (PDMS) channel with PVC sheet and a PDMS block was mounted on the piezoelectric substrate. Surface acoustic waves were used to change the volume ratio of the split daughter droplets. Splitting experiments were done using red aqueous droplets in paraffin oil. Results show that surface acoustic waves can affect the ratio of split daughter droplets. A PDMS block in one of the daughter microchannels can obviate the remerging of daughter droplets. The work is helpful for microfluidic analysis on piezoelectric microfluidic devices. [ABSTRACT FROM AUTHOR]

We investigate the stability properties of optical solitons in a chirped PT-symmetric lattice whose frequency changes in the transverse direction. Linear-stability analysis together with the direct propagation simulations demonstrates that the chirped lattice can improve the stability of optical solitons dramatically. The instability of fundamental solitons can be completely suppressed if the chirp rate exceeds a critical value. A broad stability area of dipole solitons appears if the lattice is appropriately chirped. Thus, we propose an effective way to suppress the instability of solitons in PT-symmetric potentials. [ABSTRACT FROM AUTHOR]

We investigate the existence and stability of different families of spatial solitons in optical waveguide arrays whose amplitudes obey a disordered distribution. The competition between focusing nonlinearity and linearly disordered refractive index modulation results in the formation of spatial localized nonlinear states. Solitons originating from Anderson modes with few nodes are robust during propagation. While multi-peaked solitons with in-phase neighboring components are completely unstable, multipole-mode solitons whose neighboring components are out-of-phase can propagate stably in wide parameter regions provided that their power exceeds a critical value. Our findings, thus, provide the first example of stable higher-order nonlinear states in disordered systems. [ABSTRACT FROM AUTHOR]

We study the dynamics of soliton in one-dimensional Bose gas with strong two-body losses which make the system non-conservative. Employing the perturbed variational approximation, we analytically get the dynamics equations which govern the dynamics of soliton in this open system. Our results show that the strong two-body loss rate will dramatically influence the solitons exists, amplitudes and widths, which is contrary different from conservative system without two-body loss. [ABSTRACT FROM AUTHOR]