Paper Doll Brought to Life by 'Artificial Muscles'
Researchers from Nankai University and Tianjin University in China, reporting in the American Chemical Society journal ACS Central Science , have made a foil “paper doll” sit up using polymer covalent organic frameworks (polyCOFs). The researchers say they have demonstrated, for the first time, that polyCOF membranes can be used as artificial muscles to perform various complicated motions (like doing “sit-ups” and lifting objects) triggered by vapors. This research bridges the gap between one-dimensional amorphous linear polymers and crystalline polymer frameworks, and paves the way to prepare stimuli-responsive actuators using porous COF materials. This video shows how the team made and tested these potentially useful new materials.
Transcript
00:00:06 creepy dolls that can move on their own like Annabelle and Chucky are thrilling moviegoers this summer meanwhile a much less menacing animate doll has chemists talking researchers have given a foil paper doll the ability to do sit-ups with a new material called polymer covalent organic frameworks or poly coughs conventional coughs are made of simple carbon containing molecules
00:00:30 linked with covalent bonds the ordered porous structures of coughs can store molecules such as gases or medicines for applications like carbon dioxide capture or drug delivery coughs typically exist as crystalline powders but sheets of the materials would be useful for many practical applications however when scientists try to make sheets or membranes using regular coughs they're
00:00:52 brittle and can't bend without breaking Yao Chen Sheng Qian ma Jin GA Joong and colleagues wondered if they could improve coughs mechanical properties by using linear polymers as one of the building blocks the researchers based their poly cough on an existing cough structure but they added a polymer called polyethylene glycol the polymer bridged the pore space of the cough
00:01:13 making the structure more compact and stable the scientists use the poly cough to make membranes that could be repeatedly bent twisted and stretched without damage interestingly the team found that the poly coughed membranes responded to various chemical vapors by folding up and the sheets unfolded when placed back in normal air to demonstrate how poly coughs could be used as a type
00:01:35 of artificial muscle the team made a doll using the membrane for the waste an aluminum foil for its other parts when exposed to ethanol vapors the doll sat up and when the vapors were withdrawn it laid down these steps were repeated several times making the doll do sit-ups the researchers say that the expansion of poly coughed pores upon binding the gas likely explains the dolls
00:01:57 calisthenics you