{"doi":"10.1021/acsami.5c06101","title":"Stretchable Encapsulation for Implantable Strain Sensors","abstract":"Implantable strain sensors integrated on organ surfaces can monitor organ deformations, such as bladder filling and stomach motility, thereby providing important information about their functional states. A major challenge lies in achieving large strain ranges while ensuring biocompatibility and long-term stability inside physiological fluid environments. Commonly used stretchable materials have relatively high water permeability, which can lead to degradation of sensing performance. This work presents a method to provide highly stretchable, biocompatible, compliant, and stable encapsulation for implantable capacitive strain sensors. Conformal deposition of parylene, a widely used encapsulation material with limited stretchability, followed by controlled mechanical buckling, creates microscale wrinkles in the parylene coating. A thermal annealing step reduces Young’s modulus of parylene, which converts globally buckled thick (>5 μm) parylene coating into microscale wrinkles. This simple annealing step effectively enhances the stretchability and barrier properties of the parylene coating. The resulting biocompatible wrinkled parylene encapsulation provides over 60% mechanical stretchability and a normalized water vapor transmission rate of 0.07 g mm/m 2 /day, offering one of the best combinations of barrier properties and stretchability among different encapsulation materials. In addition, the uniaxially microwrinkled encapsulation results in a more than doubled gauge factor for capacitive strain sensing by suppressing the Poisson effect. Thermally accelerated dynamic testing of encapsulated strain sensors validates their long-term stability. Additionally, strain sensing using encapsulated sensors sutured on a bladder phantom and ex vivo porcine bladders demonstrates their potential for real-time organ deformation sensing. The versatility of this encapsulation method makes it promising for a wide variety of stretchable implantable devices, supporting continuous organ monitoring and targeted therapy.","journal":"ACS Applied Materials & Interfaces","year":2025,"id":514804,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9506,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":871258,"name":"Liheng Yang","orcid":"0000-0001-6842-086X","position":1,"is_corresponding":false},{"id":1378842,"name":"Riley Jacobsen","orcid":null,"position":2,"is_corresponding":false},{"id":1378171,"name":"Jaemin Seo","orcid":"0000-0002-1499-622X","position":3,"is_corresponding":false},{"id":1378843,"name":"M. J. Wu","orcid":null,"position":4,"is_corresponding":false},{"id":654446,"name":"Hangbo Zhao","orcid":null,"position":5,"is_corresponding":false},{"id":1378170,"name":"Xinghao Huang","orcid":"0000-0003-2419-9811","position":0,"is_corresponding":true}],"reference_count":61,"raw_metadata":null,"created_at":"2026-07-19T02:48:34.431522Z","pmid":"40611475","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}