Fig. 2. SMA- and SMP-based microactuating structures and devices.

a SMA microactuator with diamond-shaped frame structures (1 µm in thickness) in the laser irradiation test⁴⁴. Copyright 2018 by Wiley. Reprinted with permission. b Schematic diagram of twining electrodes using SMP for vagus nerve stimulation and recording of ECG (left), and photos of an implanted twining electrode (inner diameter of 1 mm) on the vagus nerve (right)⁴⁹. Reproduced from ref. ⁴⁹ (2019, CC BY 4.0). c 4D printed SMP with variable modulus⁵². Copyright 2019 by ACS. Reprinted with permission. d Programming of an artificial crane using thermo and photoreversible SMP⁵⁰. Reproduced from ref. ⁵⁰ (2018, CC BY 4.0). e 3D printed SMP switch with silver conductive ink⁵¹. Copyright 2016 by Wiley. Reprinted with permission