7431
Vertically aligned carbon nanotube ( VA - CNT ) arrays , resembling gecko ' s adhesive foot hairs with additional superior mechanical , chemical and electrical properties , have been demonstrated to be a promising candidate for advanced fibrillar dry adhesives .
 Chemical: carbon
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: carbon