Shape-Memory-Alloys Enabled Actuatable Fiber Sensors via the Preform-to-Fiber Fabrication

Abstract

Integrative actuators and sensors within a single active device offer compelling capabilities in developing robotics, prosthetic limbs, and minimally invasive surgical tools. However, instrumenting smart and active devices with miniaturized sizes for easy customizability and high yield is largely restricted by the current manufacturing technologies. Here, we report the development of flexible polymer-based actuatable fiber sensors, produced by the preform-to-fiber thermal drawing process. It has both mechanical actuation realized by the incorporated shape-memory alloy (SMA) wires and biochemical sensing provided by carbon-based composite materials. The tip of such a fiber could be actuated with a high spatiotemporal resolution by the shape-memory effect. And, its integrated carbon composite exhibits intrinsically high sensitivity toward electroactive molecules. Here, we showed it can selectively detect adrenaline as low as 100 nM with the coexistence of major interferent molecules. We succeeded in using such an actuatable fiber sensor to target the bifurcated vessel model and capture the localized adrenaline information. The actuatable fiber sensor technologies developed here can greatly push the technological advancement in the soft and flexible robotic fields to include additional functions on top of their pure mechanical behaviors and open possibilities for achieving closed-loop control for high-precision operations.

Twisted fiber microfluidics: a cutting-edge approach to 3D spiral devices

“…1 a). To introduce spiral patterns within the fiber during the thermal drawing process, we developed a mini-rTDP system, which is adapted from a previously developed miniaturized system 27 . In addition to the vertical pulling motion, we incorporated rotations in the horizontal plane to achieve the desired internal spiral structures within the fibers (Fig.…”

The Development of Aptamer-Coupled Microelectrode Fiber Sensors (apta-μFS) for Highly Selective Neurochemical Sensing

“…Second, the thermaldrawing process provides high-yield in the fabrication of kilometer-long fibers, and the preparation of microsensors based on such fibers is rather straightforward and simple, so they can be adequately supplied for various experimental and clinical applications. Lastly, such a thermal drawing fabrication process also provides easy customizability in integrated functions across electrical, optical, 15 and mechanical modalities, 21 which can realize multimodal studies of neural dynamics.…”

“…Though our group was the first to develop a fiber-type biochemical sensing device for pH monitoring in the hippocampus, , an extrinsic functional component, a miniaturized field-effect sensor chip, was introduced to the fiber. And recently, a carbon-based polymer electrode with functional nanomaterials such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs) , has been successfully integrated within such fibers. Compared with conventional CFE-microelectrodes, such CNT or CNF based carbon-electrode fibers have high electrochemical performance, which can be easily produced with a high yield.…”

Design, Modeling, and Experimental Validation of an Active Microcatheter Driven by Shape Memory Effects

“…Shape memory alloys with large strains up to 8% have been commonly used in actuation elements, providing a significant driving force during their stroke course [22][23][24]. As such, SMA wires with submillimeter diameters and appropriate annealing for SME actuation greatly appeal to researchers working on developing actively controllable microcatheters for blood vessels with inner diameters of several millimeters [25][26][27]. Multiple polymers, such as polydimethylsiloxane (PDMS), hydrogel, silicone rubber, and polyethylene (PE)., have been prevalently used as the base materials of microcatheters [28][29][30][31].…”