Approximately one-third of fresh fruits are lost in the supply chain, with half the losses occurring during in-field harvesting and in-plant grading. The complexity of supply chain, waste and economic losses could be reduced through integrated non-destructive harvesting and in-field quality grading. Here we developed a self-decoupled tactile sensor for robotic soft gripper, embedding three-axis self-decoupled triboelectric soft tactile sensors across fingers. During single harvesting operation, the strategy can measure the gripping force, fruit firmness, weight by tactile sensors. Hence, integrated non-destructive harvesting and in-field quality grading can be achieved. Tactile sensors are bioinspired by the deformation mechanics of octopus suckers under normal and tangential forces. It features dual-mode TENG, integrating vertical contact-separation and horizontal sliding modes. This structure can independently respond to normal and tangential forces. It will generate a superimposed triboelectric signal with three spatially decoupled components. Consequently, the three-axis force can be easily decoupled with three triboelectric signals independently, achieving high-precision measurement within the 0-20 N range. Finally, we demonstrate the practical efficacy of the sensing strategy through in-field experi-ments. During grasping, fruit firmness is evaluated from the normal force response over time. Upon fruit detachment, tactile sensors monitor both normal and tangential forces in real-time to prevent damage. Finally, with the gripper reoriented palm-down, the fruit weight is non-destructively calculated via static equilibrium between the tangential force and the fruit's gravity. We develop a robotic sensing system for integrated, non-destructive fruit harvesting and in-field grading, thereby streamlining the supply chain, reducing waste, and enhancing food safety.
Inspired by octopus suckers, the research team developed a three-axis self-decoupled triboelectric tactile sensor and integrated it into a soft robotic harvesting gripper. During a single picking cycle, the system can simultaneously resolve multidirectional forces, assess fruit firmness, and determine fruit weight, thereby integrating non-destructive harvesting with in-field quality grading. This approach offers a new pathway for advancing intelligent agricultural robots while improving quality and reducing losses across fresh-fruit supply chains.
DOI Link:
https://doi.org/10.26599/NR.2026.94909003
About authors:
Jing Wang, female, is a laboratory technician whose research focuses on sensor packaging technologies and industrialization ,E-mail ： wangjing0416@sdau.edu.cn ； Hongjian Zhang, male, is an associate professor and Ph.D. supervisor specializing in intelligent agricultural machinery and equipment ， E-mail ： zhanghongji_an@163.com ; Jinxing Wang, male, is a professor and Ph.D. supervisor specializing in intelligent agricultural machinery and equipment ， E-mail ： jinxingw@163.com ； Wei Tang, male, is a research professor whose work focuses on triboelectrification mechanisms at multiphase interfaces, discrete sensing in wearable electronics, and contact electrocatalysis ， E-mail ： tangwei@binn.cas.cn ; Linlin Sun, male, is an associate professor and Ph.D. supervisor specializing in intelligent agricultural machinery and equipment ， E-mail ： sll8686886@163.com ； Zhengwen Chen, male, is a master ’ s student whose research focuses on intelligent triboelectric nanogenerator (TENG) sensors ， E-mail ： 2723217262@qq.com ）
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
Nano Research
An octopus-sucker inspired triboelectric self-decoupling three-axis force-sensing strategy
7-Jul-2026