This was mentioned in the Discussion part of their paper:

The activity of facial muscles involved in forming expressions such as smiles is closely linked to the development of wrinkles. One significant next step in this research is to leverage this model to enhance our understanding of the mechanisms underlying wrinkle formation. Moreover, applying this knowledge to recreate such expressions on a chip could find applications in the cosmetics industry and the orthopedic surgery industry. Additionally, this study performed actuation on a dermis equivalent by controlling mechanical actuators positioned beneath the dermis equivalent. Substituting this mechanical actuator with cultured muscle tissue presents an intriguing prospect in the realization of a higher degree of biomimetics. Examining the correlation between facial muscle contractions and resulting facial expression can offer insights into the physiological aspects of emotion, leading to new exploration in the treatment of diseases, such as facial paralysis surgery.