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manufacturing of surgical instruments and implantable bioelectronics. Printing technologies, characterized
by their adaptability and compatibility with conformal manufacturing processes, remain in an emerging
stage of research. These technologies require further investigation to improve material compatibility and
precision. Although nanoimprint and laser processing technologies are relatively mature, their applications
in micro-cylindrical electronic devices are limited and necessitate further exploration. Selecting the
appropriate fabrication technology is crucial for specific structures and applications of micro-cylindrical or
fiber-based devices. Despite advancements in fabrication techniques driving innovations and expansions in
fields such as wearable electronics, surgical robots, and implantable electronics, several significant
challenges persist for practical industrial applications. These challenges include achieving efficient high-
precision manufacturing, ensuring the biocompatibility of material systems, maintaining stability for long-
term wear or implantation, enabling system-level integration, and advancing intelligent applications.

(1) Efficient high-precision manufacturing. Micro-cylindrical surfaces, particularly fibers with diameters in
the hundreds of micrometers, exhibit ultra-high curvature, necessitating highly precise surface patterning
techniques. While rotational lithography and high-precision printing techniques show promise for
achieving high precision, challenges such as high-precision alignment during the rotation of micro-
cylindrical substrates must be addressed. Furthermore, the industrial application of micro-cylindrical
devices requires standardized and efficient manufacturing processes to enhance device consistency and
reliability.

(2) Biocompatibility of material systems. In medical and wearable applications, fibric electronics must be
evaluated for biocompatibility to avoid adverse biological reactions. It is essential to avoid the use of highly
chemically reactive metals or compounds as electrodes or sensitive layers. For implantable devices, special
attention must be paid to matching the modulus of the device structure with biological tissues, utilizing
substrates with lower modulus to mitigate damage to tissue cells.

(3) Stability for long-term wear/implantation. Micro-cylindrical electronic devices must fulfill stringent
short-term safety requirements for interventional surgeries while also ensuring long-term reliability for
wearable applications. Additionally, these devices must maintain stability as implantable electrodes or
biosensors within the body. Overcoming physical failures due to friction and fatigue, as well as chemical
failures resulting from material oxidation and decomposition, is crucial for ensuring long-term stability and
functionality.

(4) System-level integration. Integrated sensing systems are vital for practical applications. Key issues
include ensuring self-powering and wireless transmission for wearable sensing systems and addressing
crosstalk and decoupling in multi-mode sensing. Successful system-level integration involves incorporating
sensors, inductors, capacitors, resistors, and transistors onto fiber-based devices to create comprehensive
and functional sensing systems.

(5) Intelligent applications. With the rapid development of the Internet of Things (IoT) and artificial
intelligence (AI), micro-cylindrical electronic devices must incorporate more intelligent functions to expand
their application fields and enhance user convenience. For instance, in wearable devices, sensors must not
only monitor physiological parameters in real time but also process data and provide intelligent feedback.
By leveraging machine learning algorithms, these sensors can achieve more precise health monitoring and
disease prediction, thereby improving user experience and application value. In the medical field, surgical
robots equipped with micro-cylindrical sensors can facilitate more precise operations by providing real-time
monitoring of various parameters during surgery, thereby enhancing safety and outcomes.