Conversion of chemical into mechanical energy by contractile polymers performed by polymer complexation

A mechanochemical energy conversion system working upon polymer-polymer complexation between poly(methacrylic acid) (PMAA) and poly(ethylene glycol) (PEG) was studied. It was found that among PEGs of various molecular weights used, PEG with molecular weight of 2000 provided the most rapid and significant contraction of crosslinked PMAA membrane loaded 100 times the weight of dry membrane, exhibiting about 2000 g/cm² of stress. Increasing and decreasing the molecular weight of PEG from 2000 brought about gradual decrease both in the contraction and stress of the membrane. The work done per contraction per gramme of contractile substance was studied for various loads. It was found that the work done increased linearly with increasing weight of load, reaching 200 g cm.