This is the initial design. The round curved form will be in silicone with vibration motor within (vibration motor not shown on sketch). The red part is 3d printed. It is the enclosure for the body interaction vibrator development board and LiPo battery. You can plug-in the Micro USB connector for battery charging. In addition there is an on/off switch e.g. for travelling.
Here is a Video showing different BI1 cases and applications.