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Wang et al. Soft Sci 2024;4:41 https://dx.doi.org/10.20517/ss.2024.53 Page 3 of 43

Table 1. Comparison between fibric-based devices and film-based devices
Attribute Fibric devices Film devices
Flexibility High flexibility; multi-degree-of-freedom bending with Moderate flexibility; limited bending freedom
ultra-high curvature and high aspect ratio
Stretchability Easy to stretch; single-dimensional extension of Limited to stretch; low two-dimensional extension (typically
surface elements (recoverable stretch > 100%) < 5% tensile)
Breathability Excellent breathability; compact fiber volume; mesh- Poor breathability; low porosity compared to fibric devices
like structure when woven
Thickness Depending on textile thickness and design (typically > Ultra-thin designs possible (typically < 50 µm)
100 µm)
Lightweight Extremely lightweight; suitable for prolonged wearable Heavier than fibric devices; relatively high density
use
Integration of electronic Moderate integration; limited surface area; High integration; large surface area; supports diverse
components constrained high-density component integration electronic components
Adaptability for large- Easy adaptability; compact structure; expansion Difficult adaptability; exponential component increase for
area applications without major performance or flexibility loss large areas; increased manufacturing complexity

primarily focused on transferring pre-fabricated shapes or structures onto micro-cylindrical substrates,
ensuring the preservation of the material’s integrity and properties. For instance, transfer printing and
nanoimprinting techniques enable the precise replication of pre-fabricated thin films and nanoarray
structures onto micro-cylindrical and fibric surfaces [21,22] . While the equivalent manufacturing process offers
advantages of high precision and material efficiency, its application in micro-cylindrical electronics remains
challenged by issues such as alignment accuracy and structural integrity. In conclusion, the fabrication
technologies for micro-cylindrical electronics are diverse, with each method tailored to specific application
scenarios. The selection of a suitable manufacturing process must consider the trade-offs between precision,
material compatibility, and cost-efficiency to optimize device performance for targeted applications.

Micro-cylindrical electronics have a broad range of applications across fields such as flexible wearable
[23]
devices , surgical robots , and implantable medical devices . In the realm of wearable technology, fibric
[25]
[24]
sensors enable the monitoring of physiological parameters and the acquisition of health data [26,27] , thanks to
[28]
their flexible design that conforms to the human body . For instance, the integration of sensors and
processing units within micro-cylindrical electronic devices allows for real-time monitoring of vital signs,
including heart rate , blood oxygen levels , and body temperature , thereby providing users with
[5]
[30]
[29]
personalized health insights. In surgical robotics, the incorporation of sensors at the tips of surgical
instruments (e.g., needles) facilitates real-time data feedback , empowering surgeons to conduct more
[31]
precise procedures. This capability not only reduces surgical risks but also enhances success rates, offering
innovative solutions for complex, minimally invasive surgeries. The application of micro-cylindrical
electronics is particularly extensive in the field of implantable medical devices, which include implantable
stereo electroencephalogram (SEEG) electrodes , deep brain stimulation (DBS) electrodes , and
[32]
[33]
biosensors . These devices, designed for prolonged use within living organisms, must meet stringent
[34]
performance requirements, including favorable biocompatibility, long-term stability, miniaturization, and
integration. Furthermore, as medical technology continues to advance, the potential applications of micro-
[35]
[36]
cylindrical electronics, such as disease diagnosis , drug delivery and rehabilitation therapy , are
[37]
increasingly highlighted. Thus, micro-cylindrical electronics not only enhance the functionality of
traditional medical devices but also foster the development of novel medical solutions.
While micro-cylindrical electronic devices hold significant promise in both theoretical and practical
applications, their material properties, fabrication processes and potential uses remain under-explored in
existing literature. The absence of a systematic comparison and summary of micro-cylindrical substrate
materials and conformal fabrication techniques has resulted in a lack of practical guidance, particularly for