1415
Most of this research has focused on determining the microstructural and mechanical properties of samples taken from simple straight-walled structures , rather than developing a process to fabricate functional parts .
 concept or principle: research; concept or principle: microstructural; concept or principle: mechanical properties; concept or principle: samples; manufacturing process: simple; concept or principle: process; manufacturing process: fabricate
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 concept or principle: research; concept or principle: microstructural; concept or principle: mechanical properties; concept or principle: samples; manufacturing process: simple; concept or principle: process; manufacturing process: fabricate