Several studies have shown that actuation concepts such as Serial elastic actuator (SEA) can reduce peak power and energy consumption in ankle prostheses. Proper selection and design of the actuation concepts is important to unlock the power source potential. In this work, the optimization design, mechanical design, control scheme, and bench experiments of a new powered ankle-foot prosthesis is proposed. The actuation concept of this prosthesis is parallel elastic actuator (PEA) composed of electro-hydrostatic actuator (EHA) as the power kernel and a unidirectional parallel spring as the auxiliary energy storage element. After the appropriate motor and transmission ratio was selected, a dynamic model of the PEA prosthesis was built to obtain the appropriate spring parameters driven by biological data. The design of the hydraulic and mechanical system and the controller were provided for the implementation of the designed system. Bench experiments were performed to verify the performance. The results showed that the designed prosthesis meets the biomechanical dynamics requirements. This result emphasizes the feasibility of the EHA as a power source and actuator and provides new ideas for the design of ankle-foot prostheses.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9776366 | PMC |
http://dx.doi.org/10.3390/biomimetics7040234 | DOI Listing |
ACS Nano
December 2024
Department of Mechanical Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
Angew Chem Int Ed Engl
December 2024
Tianjin University, Materials Science and Engineering, CHINA.
Multispectral camouflage materials play a vital role in sophisticated multi-band electromagnetic (EM) applications. However, conventional single-band stealth is difficult to align with the growing demand for multi-band compatibility and intelligent adaptation. Herein, we report the design and synthesis of cephalopod-inspired MXene-integrated cholesteric liquid crystal elastomers (MXene-CLCEs) with multispectral camouflage capability, which was fabricated through in situ thiol-acrylate Michael addition and free-radical photopolymerization of CLCE precursor and isocyanate-mediated robust covalent chemical bonding of MXene nanocoating at the interface.
View Article and Find Full Text PDFNano Lett
December 2024
College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China.
Modern detection technology has driven camouflage technology toward multispectral compatibility and dynamic regulation. However, developing such stealth technologies is challenging due to different frequency-band principles. Here, this work proposes a design concept for a fluid-actuated multispectral compatible smart stealth device that employs a deformable mechanochromic layer/elastomer with a channeled dielectric layer.
View Article and Find Full Text PDFSci Robot
December 2024
CHARM Laboratory, Stanford, CA, USA.
Haptic devices typically rely on rigid actuators and bulky power supply systems, limiting wearability. Soft materials improve comfort, but careful distribution of stiffness is required to ground actuation forces and enable load transfer to the skin. We present Haptiknit, an approach in which soft, wearable, knit textiles with embedded pneumatic actuators enable programmable haptic display.
View Article and Find Full Text PDFAdv Mater
December 2024
Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, 250100, China.
Stretchable electronic devices that conduct strain-related electronic performances have drawn extensive attention, functioning as mechanical sensors, actuators, and stretchable conductors. Although strain-insensitive or strain-responsive nature is well-achieved separately, it remains challenging to combine these two characteristics in one single device, which will offer versatile adaptability in various working situations. Herein, a hybrid material with sign-switchable Poisson's ratio (SSPR) is developed by combining a phase-change gel based reentrantreentrant honeycomb pattern and a polydimethylsiloxane film.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!