أرسل هذا في رسالة قصيرة: Graphene and its derivatives: Switching on and off

 _____       ___     __   _      ___     ______   
|  __ \\    / _ \\  | || | ||   / _ \\  |      \\ 
| |  \ ||  | / \ || | '--' ||  | / \ || |  --  // 
| |__/ ||  | \_/ || | .--. ||  | \_/ || |  --  \\ 
|_____//    \___//  |_|| |_||   \___//  |______// 
 -----`     `---`   `-`  `-`    `---`   `------`