title: Toward cell-inspired materials that feel: measurements and modeling of mechanotransduction in droplet-based, multi-membrane arrays.
abstract: The droplet interface bilayer (DIB) was recently used to show that a 5 nm thick lipid membrane placed near a vibrating synthetic hair could transduce hair motion into electrical current. Herein, we study for the first time mechanoelectrical transduction of hair motion using multi-membrane DIB arrays formed with more than 2 droplets connected in series, and we introduce a transduction model to investigate how airflow across the hair generates current in a membrane-based hair cell. Measurements of sensing currents across every membrane in serial chains of up to 5 connected droplets demonstrate that perturbation of a single hair creates vibrations that propagate across several droplets, allowing for membranes that are not directly attached to the hair to still transduce its motion. Membranes positioned closest to the hair generate the largest currents, while those farther away produce less current due to energy loss from fluid damping. Inserting multiple hairs of different lengths into different droplets in the array yields sensing currents that exhibit multiple characteristic frequencies in addition to location specific current intensities, features that can be used to spatially localize mechanical perturbations. We also develop a transduction model that provides an order-of-magnitude approximation of the sensing current generated by a membrane in response to airflow across the hair. This model provides physical insights into how membrane-based materials can be used for sensing mechanical stimuli--just like nature does.
authors.affiliation: Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, 1512 Middle Dr, 414 Dougherty Engr. Bldg., Knoxville, TN, 37996, USA.
authors.forename: Nima
authors.initials: N
authors.lastname: Tamaddoni
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Sarles
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000138:chemical synthesis; D032701:Biomimetics / Q000295:instrumentation* / Q000379:methods; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006198:Hair Cells, Auditory / Q000502:physiology*; D006801:Humans; D008051:Lipid Bilayers / Q000737:chemistry; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008560:Membrane Fluidity / Q000502:physiology; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D044085:Microfluidics / Q000295:instrumentation*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013314:Stress, Mechanical; D014110:Touch / Q000502:physiology; D014160:Transducers, Pressure
chemical_list: D008051:Lipid Bilayers