4668
To create such lightweight structures , the wall thickness and position limits of the LS systems need to be investigated in detail .
 lightweight structures, wall thickness, limits, be
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 lightweight structures, wall thickness, limits, be