Infrared-regulated micro device for soft continuum robots

The development of small and flexible devices with various stiffness has the advantages of safe human-machine compliance and complex actuation. However, due to the limitations of the size, force, stiffness and actuation, the use of soft continuum device in complex, curved, and narrow environments remains a challenge. In this study, we propose a micro device for soft continuum robots with variable elastic modulus, submillimeter size and suitability for movement and manipulation in narrow and fragile environment. By exploiting the infrared-thermo effect and the temperature of phase transition, shape memory alloys and low melting point polymers are fabricated as the component of the device. While the device's variable elastic modulus regulated by infrared, its working mode can be switched: (1) passive compliant moving mode with low elastic modulus, which is safe and noninvasive; and (2) operation mode with high elastic modulus, injectability, and drug delivery. The infraredregulated variable-modulus segment of the device realizes variable elastic modulus for robots, whereas the end-effector covered by an electrospun structure consisted by low melting point material undertakes a safe interaction with tissue in the moving mode and the injection in the operation mode. The proposed method allows for the integration of smart biomedical materials toward the realization of wireless infrared-regulated, submillimeter-scale and variable-modulus structures for biomedical soft robots.