{"doi":"10.1063/1.5126957","title":"Novel imaging technique for non-destructive metrology and characterization of ultraviolet-sensitive polymeric microstructures","abstract":"The negative photoresist SU-8 has attracted much research interest as a structural material for creating complex three-dimensional (3D) microstructures incorporating hidden features such as microchannels and microwells for a variety of lab-on-a-chip and biomedical applications. Achieving desired topological and dimensional accuracy in such SU-8 microstructures is crucial for most applications, but existing methods for their metrology, such as scanning electron microscopy (SEM) and optical profilometry, are not practical for non-destructive measurement of hidden features. This paper introduces an alternative imaging modality for non-destructively characterizing the features and dimensions of SU-8 microstructures by measuring their transmittance of 365 nm ultraviolet (UV) light. Here, depth profiles of SU-8 3D microstructures and thin films are determined by relating UV transmittance and the thicknesses of SU-8 samples imaged in the UV spectrum through the Beer-Lambert law applied to the images on a pixel-by-pixel basis. This technique is validated by imaging the UV transmittance of several prototype SU-8 3D microstructures, including those comprising hidden hollow subsurface features, as well as SU-8 thin-films, and verifying the measured data through SEM. These results suggest that UV transmittance imaging offers a cost-effective, non-destructive technique to quickly measure and identify SU-8 microstructures with surface and hidden subsurface features unlike existing techniques.","journal":"Review of Scientific Instruments","year":2020,"id":115596,"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":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9566,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":541234,"name":"Pradeep Kumar Ramkumar","orcid":"0000-0003-3297-4996","position":1,"is_corresponding":false},{"id":449689,"name":"Laxman Saggere","orcid":"0000-0001-6429-6240","position":2,"is_corresponding":false},{"id":541233,"name":"Corey M. Rountree","orcid":"0000-0003-3298-0560","position":0,"is_corresponding":true}],"reference_count":21,"raw_metadata":null,"created_at":"2026-07-18T23:13:36.820928Z","pmid":"32259981","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":[]}