{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,11]],"date-time":"2026-09-11T16:46:29Z","timestamp":1789145189681,"version":"build-2803163510"},"reference-count":22,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2025,8,8]],"date-time":"2025-08-08T00:00:00Z","timestamp":1754611200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science Committee of the Ministry of Science and Higher Education of the Republic of Kazakhstan","award":["BR24992820"],"award-info":[{"award-number":["BR24992820"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents the development, modeling, and analysis of an autonomous active ankle prosthesis with two degrees of freedom (2-DoF), designed to reproduce movements in the sagittal (dorsiflexion\/plantarflexion) and frontal (inversion\/eversion) planes in order to enhance the stability and naturalness of the user\u2019s gait. Unlike most commercial prostheses, which typically feature only one active degree of freedom, the proposed device combines a lightweight mechanical design, a screw drive with a stepper motor, and a microcontroller-based control system. The prototype was developed using CAD modeling in SolidWorks 2024, followed by dynamic modeling and finite element analysis (FEA). The simulation results confirmed the achievement of physiological angular ranges of \u00b120\u201322 deg. in both planes, with stable kinematic behavior and minimal vertical displacements. According to the FEA data, the maximum von Mises stress (1.49 \u00d7 108 N\/m2) and deformation values remained within elastic limits under typical loading conditions, though cyclic fatigue and impact energy absorption were not experimentally validated and are planned for future work. The safety factor was estimated at ~3.3, indicating structural robustness. While sensor feedback and motor dynamics were idealized in the simulation, future work will address real-time uncertainties such as sensor noise and ground contact variability. The developed design enables precise, energy-efficient, and adaptive motion control, with an estimated average power consumption in the range of 7\u20139 W and an operational runtime exceeding 3 h per charge using a standard 18,650 cell pack. These results highlight the system\u2019s potential for real-world locomotion on uneven surfaces. This research contributes to the advancement of affordable and functionally autonomous prostheses for individuals with transtibial amputation.<\/jats:p>","DOI":"10.3390\/s25164881","type":"journal-article","created":{"date-parts":[[2025,8,8]],"date-time":"2025-08-08T09:56:42Z","timestamp":1754647002000},"page":"4881","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Design and Analysis of an Autonomous Active Ankle\u2013Foot Prosthesis with 2-DoF"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0467-1667","authenticated-orcid":false,"given":"Sayat","family":"Akhmejanov","sequence":"first","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3358-1182","authenticated-orcid":false,"given":"Nursultan","family":"Zhetenbayev","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department of Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aidos","family":"Sultan","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department of Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"},{"name":"Department of Automation and Control, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3905-6928","authenticated-orcid":false,"given":"Algazy","family":"Zhauyt","sequence":"additional","affiliation":[{"name":"Department of Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"},{"name":"Department of Automation and Control, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9712-5592","authenticated-orcid":false,"given":"Yerkebulan","family":"Nurgizat","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department of Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"},{"name":"Department of Automation and Control, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kassymbek","family":"Ozhikenov","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5941-3462","authenticated-orcid":false,"given":"Abu-Alim","family":"Ayazbay","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department of Electronic Engineering, Almaty University of Power Engineering and Telecommunications, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-6728-0748","authenticated-orcid":false,"given":"Arman","family":"Uzbekbayev","sequence":"additional","affiliation":[{"name":"Department of Robotics and Technical Tools of Automation, Satbayev University, Almaty 050013, Kazakhstan"},{"name":"Department of Automation and Control, Mukhametzhan Tynyshbayev ALT University, Almaty 050013, Kazakhstan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,8]]},"reference":[{"key":"ref_1","first-page":"457","article-title":"Bionic Ankle-Foot Prosthesis Normalizes Walking Gait for Persons with Leg Amputation","volume":"279","author":"Herr","year":"2012","journal-title":"Proc. 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