1885
Attracted by the great potential of AM , researchers investigated TO with AM constraints , focussing on generating an optimal topologically lightweight material layout , to be printed without any manufacturing problems .
 manufacturing process: AM; manufacturing process: AM; concept or principle: topologically lightweight; material: material; concept or principle: layout; material: be; manufacturing process: manufacturing
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:
 manufacturing process: AM; manufacturing process: AM; concept or principle: topologically lightweight; material: material; concept or principle: layout; material: be; manufacturing process: manufacturing