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From analyses of pressure−area isotherms and X-ray photoelectron spectra, we have demonstrated that redox-controllable molecular shuttles, in the shape of amphiphilic, bistable rotaxanes, are mechanically switchable in closely packed Langmuir films with chemical reagents. Additionally, mechanical switching has been proven to occur in closely packed Langmuir−Blodgett bilayers while mounted on solid substrates. The results not only constitute a proof of principle but they also provide the impetus to develop solid-state nanoelectromechanical systems that have the potential to reach up to the mesoscale.

SUMMARYEffective prediction of bus arrival times is important to advanced traveler information systems (ATIS). Here a hybrid model, based on support vector machine (SVM) and Kalman filtering technique, is presented to predict bus arrival times. In the model, the SVM model predicts the baseline travel times on the basic of historical trips occurring data at given time-of-day, weather conditions, route segment, the travel times on the current segment, and the latest travel times on the predicted segment; the Kalman filtering-based dynamic algorithm uses the latest bus arrival information, together with estimated baseline travel times, to predict arrival times at the next point. The predicted bus arrival times are examined by data of bus no. 7 in a satellite town of Dalian in China. Results show that the hybrid model proposed in this paper is feasible and applicable in bus arrival time forecasting area, and generally provides better performance than artificial neural network (ANN)-based methods.

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This study presents a shoe-mounted nonlinear piezoelectric energy harvester (PEH) with intent to capture energy from human walking. The PEH consists of a piezoelectric cantilever beam magnetically coupled to a ferromagnetic ball and a crossbeam. A sleeve is included to guide the travel of the ball. Experimental measurements and theoretical simulations demonstrate that the proposed design can collect energy from diverse excitation sources with different directions produced by the foot, including vibrations, swing motions, and the compressive force. The ball and the crossbeam sense the swing motion and the compressive force, respectively, and then actuate the piezoelectric beam to function. The piezoelectric beam senses the vibration along the tibial axis and generates electricity. The proposed PEH achieves the superposition of these excitations and generates multiple peaks in voltage output within one gait cycle. The output power generated by the fabricated prototype ranges from 0.03 mW to 0.35 mW when the walking velocity varies from 2 km/h to 8 km/h.