Microelectromechanical system‐based biocompatible artificial skin phantoms

Revealing the physical interactions between biomedical devices and human skin requires a scalable phantom with physical properties as close as possible to those of human skin. In this work, the authors developed an artificial phantom for the simulation of human skin. The proposed device comprises a gelatin membrane, a layer of SU‐8 photoresist, and microholes, respectively, mimicking the epidermis, stratum corneum, and sweat pores/ducts. A prototype was fabricated using microelectromechanical system and laser ablation techniques. The proposed structure includes microholes with a diameter of 20 µm and a depth of 57 µm distributed at a surface density of 620/cm 2 to simulate pores and sweat ducts. The mechanical and electrical properties of the fabricated phantom were compared with those of human skin. The electrical properties, such as resistivity and impedance, can be adjusted simply by varying the content of sodium chloride. 3T3 cells cultivated on the artificial phantom demonstrate their biocompatibility. The authors believe that the proposed phantom model and associated manufacturing scheme could be used to facilitate the testing of wearable and attachable bioelectronic devices.