Ultrasensitive Microstring Resonators for Solid State Thermomechanical Analysis of Small and Large Molecules

Area of Science:

• Materials Science
• Physical Chemistry
• Analytical Chemistry

Background:

• Conventional thermal analysis techniques face limitations in sensitivity and resolving complex physicochemical transitions.
• Understanding thermal characteristics of materials like proteins and polymers is crucial for fundamental research and industrial applications.
• Challenges remain in characterizing subtle thermal events such as amorphous relaxations and protein structural changes.

Purpose of the Study:

• To develop a highly sensitive instrumental analysis technique for rapid thermal characterization of small- and large-molecule samples.
• To overcome the sensitivity limitations of existing thermal analysis methods.
• To gain new insights into the thermal and mechanical properties of diverse materials, including proteins and polymers.

Main Methods:

• Development of an instrumental analysis technique utilizing resonating low-stress silicon nitride microstrings.
• Simple sample deposition method and postprocess data analysis for rapid thermal analysis.
• Analysis of pico- to nanogram quantities of material using microstring resonators.

Main Results:

• First measurements of amorphous alpha and beta relaxation, liquid crystalline transitions, and decomposition in small-molecule samples.
• Sensitive detection of the glass transition in polymers.
• Observation of unresolved thermal responses in proteins below denaturation, potentially indicating a solid-state glass transition.
• Agreement of detected thermal events with conventional techniques like differential scanning calorimetry and dynamic mechanical analysis.

Conclusions:

• Resonating microstring resonators offer a highly sensitive platform for rapid thermal analysis.
• The technique provides new insights into complex thermal transitions in various materials, including proteins and polymers.
• This method holds significant potential for advancing physicochemical analysis and material characterization.