Rational Design of Conductive Pathways in Flexible Tactile Sensors via Indirect 3D-Printing of Liquid Metal for High-Precision Monitoring and Recognition

A customizable 32P hydrogel applicator for brachytherapy of skin hemangioma based on machine learning and 3D-printing

Skin hemangioma is a tumor originating from skin blood vessels, which often occurs in infants and children. Brachytherapy with the 32P-based radionuclide applicator is an effective non-invasive therapeutic method. However, the inordinance of lesions is still the main challenge for precise local treatment and radiation protection of normal skins. A radionuclide applicator possessing advanced shape adaptability, favorable radionuclide biodistribution, optimized stress feature, and convenient preparation method is highly required for clinical practice. Herein, we present a customizable polyacrylamide (PAAm) hydrogel-based radionuclide applicator, integrating automatic lesion recognition via machine learning and 3D printing technology. The machine learning algorithm achieved a geometric accuracy of 98.78% in automated lesion contour recognition, providing guaranteed data support for 3D printing. The optimized hydrogel exhibited excellent mechanical properties (elastic modulus: 228 kPa, fracture toughness: 4.51 MJ m-3), rapid curing (<10 min), and promising 32P loading efficiency (>85%). Especially, this system greatly shortened the fabrication time while ensuring precise geometric matching for complex lesions. Through in vitro cell and in vivo tumor-bearing mouse models, the hydrogel loaded with 32P (P-HG) demonstrated favorable biocompatibility and effective therapeutic efficacy. It is believed that the synergy of intelligent recognition, 3D printing, and enhanced hydrogel performance can establish a promising treatment method with great practical potential for precise fitting brachytherapy of skin hemangioma.

Liquid Metal-Polymer Conductor-Based Conformal Cyborg Devices

Gallium-based liquid metal (LM) exhibits exceptional properties such as high conductivity and biocompatibility, rendering it highly valuable for the development of conformal bioelectronics. When combined with polymers, liquid metal-polymer conductors (MPC) offer a versatile platform for fabricating conformal cyborg devices, enabling functions such as sensing, restoration, and augmentation within the human body. This review focuses on the synthesis, fabrication, and application of MPC-based cyborg devices. The synthesis of functional materials based on LM and the fabrication techniques for MPC-based devices are elucidated. The review provides a comprehensive overview of MPC-based cyborg devices, encompassing their applications in sensing diverse signals, therapeutic interventions, and augmentation. The objective of this review is to serve as a valuable resource that bridges the gap between the fabrication of MPC-based conformal devices and their potential biomedical applications.