Vol.:(0123456789) MRS Advances https://doi.org/10.1557/s43580-021-00158-2 1 3 ORIGINAL PAPER Design, characterization and construction of an actuator based on shape memory alloys Ingrith Yuritsa Paez‑Pidiache 1  · Alberto Luviano‑Juárez 1  · Norma Lozada‑Castillo 1  · Eduardo Castillo‑Castañeda 2  · Hiram Reyes‑Torres 1 Received: 15 September 2021 / Accepted: 25 October 2021 © The Author(s), under exclusive licence to The Materials Research Society 2021 Abstract New biomedical technological developments such as prosthetics and orthotics require a synergistic use of actuators, sen- sors, and microcontrollers. In order to obtain lighter machines, alternative actuators such as deformable micromotors and actuators are found. Shape Memory Alloys (SMA) are materials for which the Shape Memory Efect can be used to generate controlled displacements by inducing thermal variations through electric excitation signals. The Nickel Titanium SMAs have attracted scientifc and technological attention for the development of fexible actuators. In particular, Nitinol is a material that can be trained in memory and form, reaching a large force while being light with a rapid mechanical response. This article presents a design and implementation methodology of Nitinol SMA-based actuators including a procedure of displacement characterization of the material, as well as the relations between thermal, mechanical and electric variables for a customized implementation. Introduction The National Academy of Medicine of Mexico, in collabo- ration with CONACYT in 2016, presented a book where it is mentioned that 75 amputations were performed per day, which means more than 25,000 amputations per year [1], of the total of these amputations 3–15% represent amputations of the hand at wrist height. In the U.S., approximately 185,000 amputations occur each year [2] and nearly 2 mil- lion people live with limb loss [3]. The human hand is an important and sophisticated organ, it is considered a mechanical and sensitive tool [4, 5]. Being the main organ of physical manipulation due to its two main functions: pressure and touch. Which allow you to perform movements and manipulation of objects. Therefore, for the design and construction of a hand prosthesis, several areas of mechanical and electronic engineering are involved, among others. In the search for the development of prostheses with new technologies, we fnd intelligent materials [6], for example, alloys with shape memory, electro and magneto active mate- rials, and fnally photochromic, among other materials that are still in use developing. Since its introduction [7], Shape Memory Alloys (SMA) have been considered as an alternative technology in diverse application areas of science and engineering [8, 9], in which the shape memory efect (SME) [10, 11], typically observed in nickel–titanium (NiTi) alloys, allows the material to return to its initial confguration from a low temperature. Flexinol is a commercially available SMA that is used for the design of actuators, its behavior is like an electric actuator that produces a length change with a high force/weight ratio, achieving a fast response (within the order of milliseconds). Ingrith Yuritsa Paez-Pidiache, Alberto Luviano-Juárez, Norma Lozada-Castillo, Eduardo Castillo-Castañeda and Hiram Reyes- Torres have contributed equally to this work. * Ingrith Yuritsa Paez-Pidiache ipaezp1800@alumno.ipn.mx Alberto Luviano-Juárez aluvianoj@ipn.mx Norma Lozada-Castillo gioconda@esfm.ipn.mx Eduardo Castillo-Castañeda ecastilloca@ipn.mx Hiram Reyes-Torres hreyest1400@alumno.ipn.mx 1 UPIITA, Instituto Politécnico Nacional, Av. IPN 2580 Col. Barrio la Laguna Ticomán, 07340 Mexico City, Mexico 2 CICATA Querétaro, Instituto Politécnico Nacional, Cerro Blanco 141, Colinas del Cimatario, 76090 Santiago de Querétaro, QRO, Mexico