Asadnia, MohsenKottapalli, Ajay Giri PrakashKaravitaki, K. DomenicaWarkiani, Majid EbrahimiMiao, JianminCorey, DavidTriantafyllou, Michael2016-11-182016Asadnia, Mohsen, Ajay Giri Prakash Kottapalli, K. Domenica Karavitaki, Majid Ebrahimi Warkiani, Jianmin Miao, David P. Corey, and Michael Triantafyllou. 2016. “From Biological Cilia to Artificial Flow Sensors: Biomimetic Soft Polymer Nanosensors with High Sensing Performance.” Scientific Reports 6 (1): 32955. doi:10.1038/srep32955. http://dx.doi.org/10.1038/srep32955.2045-2322http://nrs.harvard.edu/urn-3:HUL.InstRepos:29407651We report the development of a new class of miniature all-polymer flow sensors that closely mimic the intricate morphology of the mechanosensory ciliary bundles in biological hair cells. An artificial ciliary bundle is achieved by fabricating bundled polydimethylsiloxane (PDMS) micro-pillars with graded heights and electrospinning polyvinylidenefluoride (PVDF) piezoelectric nanofiber tip links. The piezoelectric nature of a single nanofiber tip link is confirmed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Rheology and nanoindentation experiments are used to ensure that the viscous properties of the hyaluronic acid (HA)-based hydrogel are close to the biological cupula. A dome-shaped HA hydrogel cupula that encapsulates the artificial hair cell bundle is formed through precision drop-casting and swelling processes. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. Functioning with principles analogous to the hair bundles, the sensors achieve a sensitivity and threshold detection limit of 300 mV/(m/s) and 8 μm/s, respectively. These self-powered, sensitive, flexible, biocompatibale and miniaturized sensors can find extensive applications in navigation and maneuvering of underwater robots, artificial hearing systems, biomedical and microfluidic devices.en-USJournal Article2016-11-1810.1038/srep32955