Abstract
Water transport in vascular plants provides remarkable opportunities for various engineering applications due to its highly efficient and powerless transportability. Several previous studies were conducted to regulate the biological responses of plants using noninvasive audible or ultrasound waves. However, the control mechanism of acoustic stimuli applied to plants has not been investigated yet. Thus, the practical application of these stimuli to real plants still exhibits technological limitations. This study experimentally investigated the effects of surface acoustic wave (SAW) frequency on plant transpiration to understand the acoustic-activated leaf transpiration and utilize the advantages of SAW. We captured consecutive images of the enhanced water transport in the test plant (Epipremnum aureum) by SAW at three different frequencies (10, 15, and 20 MHz). The dye solution at 15 MHz SAW presented the highest intensity value after 40 min of SAW stimulation. The excitation areas for 15 and 20 MHz SAWs were decreased to 42.3% and 22.6%, respectively, compared with that of 10 MHz SAW. The transpiration rates were directly measured to compare water transport enhancement quantitatively when different SAW frequencies were applied to the same plant leaves. The water transport in the leaves was maximized at 15 MHz SAW, regardless of excitation area.
Highlights
Plant transpiration is the ascending water transport in xylem vessels by evaporating water from aerial parts of leaves (Fig. 1A)
This study experimentally investigated the effects of surface acoustic wave (SAW) frequency on plant transpiration to understand the acoustic-activated leaf transpiration and utilize the advantages of SAW
To investigate the effects of SAW on plant leaf transpiration, the transport of dye solution through the leaf was visualized for 120 min a er applying 10 MHz SAW to a plant leaf (Fig. 3)
Summary
Plant transpiration is the ascending water transport in xylem vessels by evaporating water from aerial parts of leaves (Fig. 1A). The driving force to transport water from roots to leaves is highly negative Laplace pressure, which is generated on the surface of the mesophyll cell wall with nanoscale grooves.[1,2,3] Water molecules evaporate and diffuse through the tiny pores of plant leaves, which are called stomata. The opening and closing of stoma are controlled by guard cells to regulate the transpiration rate depending on environmental conditions.[1,4,5] To diffuse water molecules to the surrounding air, the stomata on the leaf surface should be opened. When the stomata are open for photosynthesis, CO2 is absorbed into the leaf, and water vapors and O2 are discharged.[1,4,5] Inspired from this plant leaf transpiration, arti cial tree and plant towers are installed to remove supersaturated CO2, cool down temperature, and control relative humidity.[6,7,8] In addition, a leaf-inspired powerless micropump was recently developed.[9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
