Self-Healable and 4D Printable Hydrogel for Stretchable Electronics

Materials with high stretchability and conductivity are used to fabricate stretchable electronics. Self-healing capability and four-dimensional (4D) printability are becoming increasingly important for these materials to facilitate their recovery from damage and endow them with stimuli-response properties. However, it remains challenging to design a single material that combines these four strengths. Here, a dually crosslinked hydrogel is developed by combining a covalently crosslinked acrylic acid (AAC) network and Fe3+ ions through dynamic and reversible ionically crosslinked coordination. The remarkable electrical sensitivity (a gauge factor of 3.93 under a strain of 1500%), superior stretchability (a fracture strain up to 1700%), self-healing ability (a healing efficiency of 88% and 97% for the mechanical and electrical properties, respectively), and 4D printability of the hydrogel are demonstrated by constructing a strain sensor, a two-dimensional touch panel, and shape-morphing structures with water-responsive behavior. The hydrogel demonstrates vast potential for applications in stretchable electronics.

Shared control of a medical robot with haptic guidance

PURPOSE

Tele-operation of robotic surgery reduces the radiation exposure during the interventional radiological operations. However, endoscope vision without force feedback on the surgical tool increases the difficulty for precise manipulation and the risk of tissue damage. The shared control of vision and force provides a novel approach of enhanced control with haptic guidance, which could lead to subtle dexterity and better maneuvrability during MIS surgery.

METHODS

The paper provides an innovative shared control method for robotic minimally invasive surgery system, in which vision and haptic feedback are incorporated to provide guidance cues to the clinician during surgery. The incremental potential field (IPF) method is utilized to generate a guidance path based on the anatomy of tissue and surgical tool interaction. Haptic guidance is provided at the master end to assist the clinician during tele-operative surgical robotic task.

RESULTS

The approach has been validated with path following and virtual tumor targeting experiments. The experiment results demonstrate that comparing with vision only guidance, the shared control with vision and haptics improved the accuracy and efficiency of surgical robotic manipulation, where the tool-position error distance and execution time are reduced.

CONCLUSIONS

The validation experiment demonstrates that the shared control approach could help the surgical robot system provide stable assistance and precise performance to execute the designated surgical task. The methodology could also be implemented with other surgical robot with different surgical tools and applications.

A bioabsorbable microclip for laryngeal microsurgery: design and evaluation

Epithelial flaps created during laryngeal microsurgery require apposition to facilitate proper healing. Current technologies are restricted by minimal access of the surgical site, posing various limitations in application. In this paper, we propose a novel magnesium-based bioabsorbable microclip, discuss our design considerations and evaluate the microclip's feasibility as a miniature wound closure device. Ex vivo experiments demonstrate that the microclip fastens securely to the vocal fold, while in vivo studies show bioabsorbability and a lack of adverse side effects, suggesting that the microclips are viable as implantable devices.