U.S. patent application 20180177280 (applicant HCT Group Holdings Ltd., China):
"Cosmetics packaging and applicators including a gel based tip are described. Gel applicators may or may not be provided with a through-hole. In various embodiments, the gel may be a stand-alone gel or may be encapsulated in a membrane. The gel applicator provides a soft feel and may have cooling effect as well. In some embodiments, the applicator is mounted to a platform or a hollow insert and coupled to a container housing the cosmetics product. ... The gel may also include phase change materials which are useful in conveying the cooling sensation, since phase change materials, by definition absorb heat energy when changing phases."