Fluctuation spectra and force generation in nonequilibrium systems
Many biological systems are appropriately viewed as passive inclusions immersed in an active bath: from proteins on active membranes to microscopic swimmers confined by boundaries. The nonequilibrium forces exerted by the active bath on the inclusions or boundaries often regulate function, and such...
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| Format: | Journal article |
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National Academy of Sciences
2017
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| _version_ | 1797091211144593408 |
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| author | Lee, A Vella, D Wettlaufer, J |
| author_facet | Lee, A Vella, D Wettlaufer, J |
| author_sort | Lee, A |
| collection | OXFORD |
| description | Many biological systems are appropriately viewed as passive inclusions immersed in an active bath: from proteins on active membranes to microscopic swimmers confined by boundaries. The nonequilibrium forces exerted by the active bath on the inclusions or boundaries often regulate function, and such forces may also be exploited in artificial active materials. Nonetheless, the general phenomenology of these active forces remains elusive. We show that the fluctuation spectrum of the active medium, the partitioning of energy as a function of wavenumber, controls the phenomenology of force generation. We find that for a narrow, unimodal spectrum, the force exerted by a non-equilibrium system on two embedded walls depends on the width and the position of the peak in the fluctuation spectrum, and oscillates between repulsion and attraction as a function of wall separation. We examine two apparently disparate examples: the Maritime Casimir effect and recent simulations of active Brownian particles. A key implication of our work is that important non-equilibrium interactions are encoded within the fluctuation spectrum. In this sense the noise becomes the signal. |
| first_indexed | 2024-03-07T03:29:44Z |
| format | Journal article |
| id | oxford-uuid:ba4c248d-b1c1-4d6e-b853-1e8da595e4db |
| institution | University of Oxford |
| last_indexed | 2024-03-07T03:29:44Z |
| publishDate | 2017 |
| publisher | National Academy of Sciences |
| record_format | dspace |
| spelling | oxford-uuid:ba4c248d-b1c1-4d6e-b853-1e8da595e4db2022-03-27T05:08:48ZFluctuation spectra and force generation in nonequilibrium systemsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ba4c248d-b1c1-4d6e-b853-1e8da595e4dbSymplectic Elements at OxfordNational Academy of Sciences2017Lee, AVella, DWettlaufer, JMany biological systems are appropriately viewed as passive inclusions immersed in an active bath: from proteins on active membranes to microscopic swimmers confined by boundaries. The nonequilibrium forces exerted by the active bath on the inclusions or boundaries often regulate function, and such forces may also be exploited in artificial active materials. Nonetheless, the general phenomenology of these active forces remains elusive. We show that the fluctuation spectrum of the active medium, the partitioning of energy as a function of wavenumber, controls the phenomenology of force generation. We find that for a narrow, unimodal spectrum, the force exerted by a non-equilibrium system on two embedded walls depends on the width and the position of the peak in the fluctuation spectrum, and oscillates between repulsion and attraction as a function of wall separation. We examine two apparently disparate examples: the Maritime Casimir effect and recent simulations of active Brownian particles. A key implication of our work is that important non-equilibrium interactions are encoded within the fluctuation spectrum. In this sense the noise becomes the signal. |
| spellingShingle | Lee, A Vella, D Wettlaufer, J Fluctuation spectra and force generation in nonequilibrium systems |
| title | Fluctuation spectra and force generation in nonequilibrium systems |
| title_full | Fluctuation spectra and force generation in nonequilibrium systems |
| title_fullStr | Fluctuation spectra and force generation in nonequilibrium systems |
| title_full_unstemmed | Fluctuation spectra and force generation in nonequilibrium systems |
| title_short | Fluctuation spectra and force generation in nonequilibrium systems |
| title_sort | fluctuation spectra and force generation in nonequilibrium systems |
| work_keys_str_mv | AT leea fluctuationspectraandforcegenerationinnonequilibriumsystems AT vellad fluctuationspectraandforcegenerationinnonequilibriumsystems AT wettlauferj fluctuationspectraandforcegenerationinnonequilibriumsystems |