Small-scale continuum robots hold promise for interventional diagnosis and treatment, yet existing models struggle to achieve small size, precise steering, and visualized functional treatment simultaneously, termed an “impossible trinity”. This study introduces an optical fiber-based continuum robot integrated imaging, high-precision motion, and multifunctional operation abilities at submillimeter-scale. With a slim profile of 0.95 mm achieved by microscale 3D printing and magnetic spray, this continuum robot delivers competitive imaging performance and extends obstacle detection distance up to ~9.4 mm, a tenfold improvement from the theoretical limits. Besides, the robot showcases remarkable motion precision (less than 30 μm) and substantially widens the imaging region by ~25 times the inherent view. Through ex vivo trials, we validate the robot’s practicality in navigating constrained channels, such as the lung end bronchus, and executing multifunctional operations including sampling, drug delivery, and laser ablation. The proposed submillimeter continuum robot marks a significant advancement in developing biomedical robots, unlocking numerous potential applications in biomedical engineering.
Defects, such as uncontrollable vacancies, will intensively degrade the material properties and device performance of CVD-grown transition metal dichalcogenides (TMDs). Although vacancies can be repaired by some post-processing measures, these treatments are usually time-consuming, complicated and may introduce uncontrollable chemical contaminants into TMDs. How to efficiently suppress the uncontrollable defects during CVD growth and acquire intrinsic high-quality CVD-grown TMDs without any after-treatment remains a critical challenge, and has not yet been well resolved. Here, an alternate-growth-etching (AGE) CVD method was demonstrated to fabricate defect-suppressed submillimeter-scale monolayer WS2 single crystals. Compared with normal CVD, the grain size of the as-grown WS2 can be enlarged by 4–5 times (∼520 μm) and the growth rate of ∼14.4 μm min−1 is also at a high level compared to reported results. Moreover, AGE-CVD can efficiently suppress atomic vacancies in WS2. In every growth-etching cycle, the etching of WS2 occurs preferentially at the defective sites, which will be healed at the following growth stage. As a result, WS2 monolayers obtained by AGE-CVD possess higher crystal quality, carrier mobility (8.3 cm2 V−1 s−1) and PL quantum yield (QY, 52.6%) than those by normal CVD. In particular, such a PL QY is the highest value ever reported for in situ CVD-grown TMDs without any after-treatment, and is even comparable to the values of mechanically exfoliated samples. This AGE-CVD method is also appropriate for the synthesis of other high-quality TMD single crystals on a large-scale.
危险品化学品经营许可证（带存储）