For medical devices that are implanted or attached to the skin, another important property requiring consideration is the flexural rigidity, "D". Flexural rigidity will determine how well the device surface can maintain contact with the tissue surface, which is especially important for devices that are measuring tissue motion (strain), electrical signals (impedance), or are designed to stick to the skin without delaminating, as in epidermal electronics. Since flexural rigidity depends on the thickness of the material, "h", to the third power ("h"3), it is very important that a biomaterial can be formed into thin layers in the previously mentioned applications where conformality is paramount.