RESUMEN
With existent biomechanical models of skeletal muscle, challenges still exist in implementing real-time predictions for contraction statuses that are particularly significant to biomechanical and biomedical engineering. Because of this difficulty, this paper proposed a decoupled scheme of the links involved in the working process of a sarcomere and established a semiphenomenological model integrating both linear and nonlinear frames of no higher than a second-order system. In order to facilitate engineering application and cybernetics, the proposed model contains a reduced number of parameters and no partial differential equation, making it highly concise and computationally efficient. Through the simulations of various contraction modes, including isometric, isotonic, successive stretch and release, and cyclic contractions, the correctness and efficiency of the model, are validated. Although this study targets half-sarcomeres, the proposed model can be easily extended to describe the larger-scale mechanical behavior of a muscle fiber or a whole muscle.
Asunto(s)
Fenómenos Mecánicos , Modelos Biológicos , Sarcómeros/fisiología , Fenómenos Biomecánicos , Contracción Isométrica , Contracción Isotónica , Cinética , Factores de TiempoRESUMEN
Shape memory alloy (SMA) has great potential to develop light and compact artificial muscle (AM) due to its muscle-like high power-to-weight ratio, flexibility and silent operation properties. In this paper, SMA self-sensing properties are explored and modeled in depth to imitate the integrated muscle-like functions of actuating and self-sensing for SMA-AM based on the investigation of SMA electrical resistivity (ER). Firstly, an ER transformation kinetics model is proposed based on the simulation of SMA differential scanning calorimetry (DSC) curves. Then a series of thermal-electrical-mechanical experiments are carried out to verify the validity of the ER model, whereby the SMA-AM self-sensing function is well established under different stress conditions. Finally the self-sensing capability is further demonstrated by its application to a novel SMA-AM-actuated active ankle-foot orthosis (AAFO).
Asunto(s)
Aleaciones/química , Biomimética/instrumentación , Conductometría/instrumentación , Ortesis del Pié , Modelos Biológicos , Músculo Esquelético/fisiología , Transductores , Simulación por Computador , Diseño Asistido por Computadora , Impedancia Eléctrica , Diseño de Equipo , Análisis de Falla de Equipo , Retroalimentación , HumanosRESUMEN
In the present paper, bulk heterojunction polymer solar cells based on P3HT:PCBM and P3HT:PCBM:QDs active layer were fabricated and measured respectively. The experimental result showed that the addition of QDs can broaden the spectral response and enhance photoinduced electron transfer. The conversion efficiency of device with QDs is about 25% higher than that without QDs.