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Control of McKibben Polymeric Artificial Muscles by Means of Buffer Solutions
Author(s) -
Tondu B.,
Mathé S.,
Emirkhanian R.
Publication year - 2010
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201051034
Subject(s) - swelling , artificial muscle , isometric exercise , buffer (optical fiber) , polymer , weak base , chemistry , materials science , polymer chemistry , actuator , composite material , organic chemistry , computer science , medicine , telecommunications , artificial intelligence , physical therapy
Reversible swelling and de‐swelling of pH reactive polymers are mainly made using strong bases and strong acids, typically with pH equal to 0 or 1 and 14 or 13. As a consequence, pH‐artificial muscles are triggered off at a pH too high for internal use of such muscles inside the human body. The paper analyses the possibility of using weak base‐weak acid buffers to generate the ion circulation necessary for swelling/de‐swelling phenomena with a limited pH‐range. The paper further reports experiments with ion‐exchange resins swelling and de‐swelling in response to standard NaHCO 3 /CH 3 COOH + CH 3 COONa weak base‐weak acid solutions. The ion exchange resin is placed inside the inner tube of a McKibben‐braided structure whose functioning we have discussed elsewhere in connection with its reliability to define a chemo‐mechanical artificial muscle with static and dynamic behaviour close to human skeletal muscle. We experimentally show that a 0.25 M buffer solution leads to a maximum isometric force and a contraction time response similar to that obtained with 0.1 M NaOH/HCl strong base‐strong acid. As a consequence, our McKibben polymeric artificial muscle is now controlled within a 3.8 pH‐range: muscle contraction is triggered at about 8.3 pH, and muscle relaxation at about a 4.5 pH. The dynamic performance of a 170 mm long/7 mm diameter in isotonic mode, with loads between 0.25 kg to 10 kg, is reported.