Compositions and articles comprising omniphobic materials for bio-related and other applications are generally provided. In some embodiments, the compositions and articles described herein may be introduced internally of a subject (e.g., in the esophagus, in the gastrointestinal tract, in the rectum). In some aspects, the compositions and articles comprise a releasable therapeutic agent In some embodiments, the compositions and articles described herein may be configured to have a relatively short retention time at the location internal of the subject (e.g., less than 2 seconds) such as a capsule comprising an omniphobic coating. In alternative embodiments, the compositions and articles described herein may be configured to have relative long retention times at the location internal of the subject (e.g., greater than 10 minutes) and include a mucoadhesive portion as well as an omniphobic portion. Such articles may have an omniphobic portion which resists adhesion and/or fouling (e.g., by foodstuffs and/or other materials present internal of the subject) of the article, such that the mucoadhesive portion maintains adhesion to the location internal of the subject for relatively long retention times. In some such embodiments, the article may be a Janus-type device.Linvention concerne des compositions et des articles comprenant des matériaux omniphobes destinés à des applications biologiques et autres. Selon certains modes de réalisation, les compositions et articles de la présente invention peuvent être introduits à lintérieur dun sujet (par exemple, dans lœsophage, dans le tractus gastro-intestinal, dans le rectum). Selon certains aspects, les compositions et articles comprennent un agent thérapeutique libérable. Selon certains modes de réalisation, les compositions et articles de la présente invention peuvent être conçus pour présenter un temps de rétention relativement court à lemplacement interne du sujet (par exemple, moins de 2 secondes) tels quune capsule compre