Sandworm

Florian J. Egloff, M. Smeets

Andy Greenberg is a rightly adored technology writer. His extensive reporting on some of the most important issues in privacy and cybersecurity lends him great credibility to write on ‘Russia's rec...

Yichi Zhang, Guangyu Wu, Fukang Feng, Changyao Gao, Xinjie Jin, Xiaoyu Zhang, Weinan Xing

Shoujie Li, Changqing Guo, Junhao Gong, Chenxin Liang, Wenhua Ding, Wenbo Ding

Perception in granular media remains challenging due to unpredictable particle dynamics. To address this challenge, we present SandWorm, a biomimetic screwactuated robot augmented by peristaltic motion to enhance locomotion, and sandworm tactile sensor (SWTac), a novel event-based visuotactile sensor with an actively vibrated elastomer. The event camera is mechanically decoupled from vibrations by a spring isolation mechanism, enabling high-quality tactile imaging of both dynamic and stationary objects. For algorithm design, we propose an IMU-guided temporal filter to enhance imaging consistency, improving masked signal-to-noise ratio (MSNR) by 24%. Moreover, we systematically optimize SWTac with vibration parameters, event camera settings, and elastomer properties. Motivated by asymmetric edge features, we also implement contact surface estimation by U-Net. Experimental validation demonstrates SWTac’s 0.2 mm texture resolution, 98% stone classification accuracy, and 0.15 N force estimation error, while SandWorm demonstrates versatile locomotion (up to 12.5 mm/s) in challenging terrains, successfully executes pipeline dredging and subsurface exploration in complex granular media (observed 90% success rate). Field experiments further confirm the system’s practical performance.

J. Sevilla-Nastor, T. Sakurai, M. J. Mozo, J. Villanueva

Bora Kim, M. O. Jun, Ah-In Yang, Sung-Hong Joe, H. Joe, Hojun Sung, Ki Hyun Kim, Hyun Jung Kim, Na-Ri Shin

A novel Gram-stain-positive, facultatively anaerobic, non-motile, catalase-positive, oxidase-negative and ovoid cocci, designated as A1S7T, was isolated from the gut of a marine sandworm (Alitta virens). Strain A1S7T exhibited optimal growth at temperatures of 20-30 ℃, pH 6-8 and in the presence of 2-4% (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain A1S7T belonged to the genus Janibacter, exhibiting a similarity of 99.0% to Janibacter cremeus KCTC 49873T, followed by Janibacter anophelis KCTC 19282T (98.8%), Janibacter hoylei KCTC 49872T (98.4%), Janibacter limosus KACC 20518T (98.2%) and Janibacter corallicola KACC 21120T (97.2%). The complete genome sequence of strain A1S7T revealed a genome size of 3360920 bp with a genomic G+C content of 70.1 mol%. The orthologous average nucleotide identity and the digital DNA-DNA hybridization values between strain A1S7T and Janibacter cremeus KCTC 49873T were determined to be 89.5 and 37.2%, respectively. The major respiratory quinone was MK-8(H4). The predominant fatty acids (>10%) included iso-C16:0, C17:1  ω8c, C18:1  ω9c and C17:0. Polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, one unknown phosphoglycolipid and three unknown polar lipids. The cell-wall peptidoglycan type was A1γ. The major whole-cell sugars were ribose, mannose and glucose. Based on phenotypic, phylogenetic, genotypic and chemotaxonomic properties, strain A1S7T represents a novel species in the genus Janibacter, for which the name Janibacter alittae sp. nov. is proposed. The type strain is A1S7T (=KCTC 49714T = JCM 36706T).