A material developed for space suits has been found useful in a completely different application: making wicks to support seedlings and to carry water and nutrients to them during the initial stages of hydroponic growth. A modified version of the wick material may also prove useful in wick-based evaporators and humidifiers.
The wick material consists of a middle layer of polyethylene sandwiched between layers of woven glass fibers. The layers are fused together by heating and pressing. Sheets of the material are bent into U-shaped wicks, which are positioned with the tips immersed in an aqueous nutrient solution (see figure). The wick material is chemically inert with respect to the nutrient solution.
Seeds are nested between adjacent wicks. The hydrophilic nature of the fibers and their tight weave ensures wicking of moisture and nutrients to the seeds and, eventually, to the roots. The wicks support roots in the sense that root hairs can cling to the glass fabric, but the tight weave resists penetration by the roots. Seedlings can therefore be removed with little or no damage to the roots, and wicks can be reused.
This work was done by Daniel J. Barta of Johnson Space Center and Robert W. Spanarkel of Lockheed Engineering and Sciences Co. MSC-22539