{"created":"2023-06-19T12:47:41.571119+00:00","id":8154,"links":{},"metadata":{"_buckets":{"deposit":"0761233c-062c-4015-9446-92a228a1745a"},"_deposit":{"created_by":3,"id":"8154","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"8154"},"status":"published"},"_oai":{"id":"oai:tokyo-metro-u.repo.nii.ac.jp:00008154","sets":["465:473:474:865:1583"]},"author_link":["25629","25630","25628"],"item_2_alternative_title_19":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"粘弾性体中を遊泳するマイクロマシン"}]},"item_2_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2018-03-25","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"148","bibliographicPageStart":"1","bibliographic_titles":[{}]}]},"item_2_creator_2":{"attribute_name":"著者(ヨミ)","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"ヤスダ, ケント"}],"nameIdentifiers":[{"nameIdentifier":"25629","nameIdentifierScheme":"WEKO"}]}]},"item_2_creator_3":{"attribute_name":"著者別名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"安田, 健人"}],"nameIdentifiers":[{"nameIdentifier":"25630","nameIdentifierScheme":"WEKO"}]}]},"item_2_date_granted_66":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2018-03-25"}]},"item_2_degree_grantor_64":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"首都大学東京"}]}]},"item_2_degree_name_63":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"修士（理学）"}]},"item_2_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Microswimmers are tiny machines that swim in a fluid, such as sperm cells or motile bacteria, and they are expected to be applied to microfluidics and microsystems. By transforming chemical energy into mechanical work, microswimmers change their shape and move in viscous environments. Over the length scale of microswimmers, the fluid forces acting on them are governed by the effect of viscous dissipation. According to Purcell's scallop theorem, time-reversal body motion cannot be used for locomotion in a Newtonian fluid. As one of the simplest models exhibiting broken time-reversal symmetry, Najafi and Golestanian proposed a three-sphere swimmer, in which three in-line spheres are linked by two arms of varying length. First, we discuss the locomotion of a three-sphere microswimmer in a viscoelastic medium and propose a new type of active microrheology. We derive a relation that connects the average swimming velocity and the frequency-dependent viscosity of the surrounding medium. In this relation, the viscous contribution can exist only when the time-reversal symmetry is broken, whereas the elastic contribution is present only when the structural symmetry of the swimmer is broken. Purcell's scallop theorem breaks down for a three-sphere swimmer in a viscoelastic medium. Next, we discuss the dynamics of a generalized three-sphere microswimmer in which the spheres are connected by two elastic springs. The natural length of each spring is assumed to undergo a prescribed cyclic change. We analytically obtain the average swimming velocity as a function of the frequency of cyclic change in the natural length. In the low-frequency region, the swimming velocity increases with frequency, and its expression reduces to that of the original three-sphere model by Najafi and Golestanian. Conversely, in the high-frequency region, the average velocity decreases with increasing frequency. Such behavior originates from the intrinsic spring relaxation dynamics of an elastic swimmer moving in a viscous fluid. Finally, we discuss the directional motion of an elastic three-sphere micromachine in which the spheres are in equilibrium with independent heat baths having different temperatures. Even in the absence of prescribed motion of the springs, such a micromachine can gain a net motion due purely to thermal fluctuations. A relation connecting the average velocity and the temperatures of the spheres is analytically obtained. This velocity can also be expressed in terms of average heat flows in the steady state. Our model suggests a new mechanism for locomotion of micromachines in nonequilibrium biological systems.","subitem_description_type":"Abstract"}]},"item_2_description_5":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"首都大学東京, 2018-03-25, 修士（理学）","subitem_description_type":"Other"}]},"item_2_version_type_16":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_ab4af688f83e57aa","subitem_version_type":"AM"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Yasuda, Kento"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2020-02-18"}],"displaytype":"detail","filename":"T01584-001.pdf","filesize":[{"value":"1.6 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"T01584-001.pdf","url":"https://tokyo-metro-u.repo.nii.ac.jp/record/8154/files/T01584-001.pdf"},"version_id":"e15e4163-3e69-45f1-89cf-30c96a2a58bb"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Micromachines swimming in viscoelastic fluids","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Micromachines swimming in viscoelastic fluids"}]},"item_type_id":"2","owner":"3","path":["1583"],"pubdate":{"attribute_name":"公開日","attribute_value":"2020-03-06"},"publish_date":"2020-03-06","publish_status":"0","recid":"8154","relation_version_is_last":true,"title":["Micromachines swimming in viscoelastic fluids"],"weko_creator_id":"3","weko_shared_id":3},"updated":"2023-06-19T15:55:48.641865+00:00"}