{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T17:24:13Z","timestamp":1792171453747,"version":"4.4.0"},"reference-count":81,"publisher":"SAGE Publications","license":[{"start":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T00:00:00Z","timestamp":1779753600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Soft Robotics"],"abstract":"<jats:p>Soft robots require tactile sensors capable of quantifying the mechanical properties of unknown objects during manipulation, yet most existing approaches are fragile, costly, or limited in dynamic range. Here, we present a model-guided plant-inspired hydraulic tactile sensor in which contact-induced deformation of a compliant elastomer generates a measurable pressure change in an embedded liquid-filled channel. By combining pressure and deformation measurements with an analytical elastic\u2013hydraulic contact model, the effective Young\u2019s modulus of the contacted spherical object can be inferred without direct force sensing. The accessible stiffness range is set by the sensor\u2019s elastic modulus and channel geometry; we demonstrate this design tunability using four sensor variants, enabling accurate stiffness estimation over more than two orders of magnitude. Integrated into a low-cost (under US$50) three-dimensional\u2013printed robotic arm, the sensor performs real-time modulus estimation under quasi-static conditions using measurements of object diameter, deformation, and internal pressure. A predictable operating window, expressed as the stiffness ratio between the object and the sensor, maximizes measurement accuracy within the model\u2019s linear-elastic regime. Validation on synthetic polymers and fresh produce demonstrates applications ranging from laboratory material characterization to nondestructive monitoring of fruit ripening, advancing accessible and quantitative tactile sensing for soft robotic systems.<\/jats:p>","DOI":"10.1177\/21695172261453210","type":"journal-article","created":{"date-parts":[[2026,5,26]],"date-time":"2026-05-26T13:03:37Z","timestamp":1779800617000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":1,"title":["Plant-Inspired Elastic\u2013Hydraulic Tactile Sensing Enables Quantitative Stiffness Estimation in Soft Robots"],"prefix":"10.1177","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-8530-0058","authenticated-orcid":false,"given":"Tofayel Ahammad","family":"Ovee","sequence":"first","affiliation":[{"name":"Chemical Engineering, Auburn University, Auburn, Alabama, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-2841-2259","authenticated-orcid":false,"given":"Eftakhar Ahmed","family":"Arnob","sequence":"additional","affiliation":[{"name":"Computer Science and Software Engineering Department, Auburn, University, Auburn, Alabama, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1971-4209","authenticated-orcid":false,"given":"Jean-Fran\u00e7ois","family":"Louf","sequence":"additional","affiliation":[{"name":"Chemical Engineering, Auburn University, Auburn, Alabama, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2026,5,26]]},"reference":[{"key":"e_1_3_3_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/nature14543"},{"key":"e_1_3_3_3_1","doi-asserted-by":"publisher","DOI":"10.3390\/s21082689"},{"key":"e_1_3_3_4_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ifset.2011.03.002"},{"key":"e_1_3_3_5_1","doi-asserted-by":"crossref","unstructured":"4.Milojevi\u0107 A Lin\u00df S Handroos H. 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