Researchers from Virginia Tech's Future Materials Laboratory and Minds Laboratory have Recently Demonstrated that High-Intensity Focused Ultrasound (HIFU) is a promising, non-invasive stimulus with multiple superiior and unique capability to induce localized heating and Thermal spatial Effects in Polymers.
The team proposals a new manner of stimulating stimuli-response polymers. These polymers Demonstrate Promise for Controlled Drug Delivery, Sensing and Biosensing, Smart Coatings, Soft Robotics, and Flexible Electronics Among Others.
Accordingly, the capacity to manipulate these polymers is well sought after, but has proven challenging due to outlet with the stimuli used to manipulate the polymers.
Traditionally Such Polymers Have Been Stimulated via Direct Heat, but this can damage heat-sensitive materials. Other techniques included irradiation, Electric Current, and Magnetic Fields Have also Been Used. Such Techniques, However, reduce the efficiency of the polymer's responsiveness.
This recent Study (Nanotechnology, "Interaction of High-Intensity Focused Ultrasound With Polymers Attistic Scale") has demonstrated that these polymers can be stimulated by High Frequency Ultrasound (HIFU), Which May bypass a variety of the Precipitated by other technical.
HIFU Transmits and Focuses Sound from A Transducer Into A Small Focal Point. These sound waves interact with polymer chains in a select are, vibrating them and causing significant local heating effects necessary to stimulate the polymer, while leaving the surrounding isrea largely unaffected.
The Energy from the hifu waves is both translated into dissipated heat and elastic deformation of the polymer chains.WHEREAS conventional heating produces largely uniform changes in polymers, hifu confers different thermal effects. This may be due to the different internal friction of macromolecular chains. The Particle Velocity Distribution and Material Thickness Have Been Found To Be Responsible for the Different Heating Effects. Experiments Suggest that a ranges of factors are responsible for the ultrasound induced changes in polymers.
Experiment have proven insufficient for establishing the ranges of effects caused by ultrasound on polymers, due to the low granularity provided by such experience. Instead, Computer Modeling has been used to track the changes in polymers caused by hifu heating.
Molecular Dynamics (MD) Models Allow Scientists to Study the Mechanical and Thermal Properties of Polymers, As Every Atom in the System can be recorded Alongside the Evolution of the Chain Orientation.
This recent study investigated the ultrasound-induced thermal effects at the atomic scale by md stimulation. The Team Performed Experiment to Galvanize Their Computer Models, with a focus on chain arrangement and structure in responsibility to thermal effects. Low and High-Density Polyethylene (LDPE and HDPE ATHEFULLY) WERE STUDIED AS Counterparts.
This is the first study to explore the ultrasound-induced thermal effects on polymers at the atom scale, which explains the observed responsibilities at the macroscale.
The Experiments Found that Under Focused Ultrasounds With Equal Power, The Heating Rate of Amorphous Ldpe is Larger that of Crystalline HDPE. MD Simulations we were used to elucidate the mechanisms of this different. The Scientists examine Tha Mechanisms at Different Scales. At the Larger System Level, the Frequency Dependent Viscoelasticity is the Direct Factor. At the molecular chain level the thermal motion of chains is great in ldpe Than it is in hdpe. Indications suggest that at the atom level, ldpe atoms are more flexible Than Those in HDPE.
As the Field of Polymer Manipulation Continues to Expand, New Manners of Manipulating Polymers Are of Paramount Importance for Propeling the Discipline. The novel Research Into Hifu Manipulation of Polymers OpenS The Door For Further Developments, and Allows Future Researchers to Use Similar Modeling Systems when Investigating Polymeric Effects.