Magnetostrictive Response of Cellulose Nanofibril Composites Nathan Swanson - Mechanical Engineering Dr. Chiu Tai Law - Electrical Engineering and Computer Science Dr. Rani Elhajjar – Civil and Environmental Engineering

Overview Objectives Background Previous Research Methodology and Processing Multiphysics Modeling Testing Results Future Research Practical Applications

Background Magnetostriction Strain Characterization 𝜖 𝐻 = Δλ 0.78𝜆 𝐵 0.78 is the photoelastic strain constant. 𝜆 𝐵 Braggs Grating initial wavelength. Magnetostrictive Strain Coefficient 𝑑 33 = 𝑑𝜖 𝑑𝐻 H is the applied field Coupling Factor 𝑘 33 2 = 𝑑 33 2 𝜇 33 𝑇 𝐸 𝐻 𝑑 33 : magnetostrictive strain coefficient. 𝜇 33 𝑇 : relative permeability at a constant stress. 𝐸 𝐻 : Young’s Modulus at a constant applied field.

Objectives Embed a Cable Characterize Magnetostriction Validate previous research

Previous Research Optimal Volume Fraction Adhered Layers Material Properties Relative Strain

Methodology and Processing Water Extraction 2 Layers Embedding a wire Flat Aluminum flats

Multiphysics Modeling 𝜖 −398762 =330.1 𝑝𝑝𝑚 𝑑 33 =1330 𝑝𝑚 𝐴 𝑘 33 =22.027∗ 10 −3

Testing Sweeping the Field Change in the Reflected Spectrum Describe Process by which samples were tested with the breaking and SEM Describe importance of gaps being very small so particles had adequate CNF matrix to do work against during magnetization Show how gaps around 3 micro meters would be sufficient to handle 100 – 150 micrometer particles. 𝜖 −398762 =91.23 𝑝𝑝𝑚

Results Describe Process by which samples were tested with the breaking and SEM Describe importance of gaps being very small so particles had adequate CNF matrix to do work against during magnetization Show how gaps around 3 micro meters would be sufficient to handle 100 – 150 micrometer particles. 𝑑 33 =275 𝑝𝑚 𝐴 𝑘 33 =4.559∗ 10 −3

Future Research 413 𝑝𝑚 𝐴 <𝑑 33 <826 𝑝𝑚 𝐴 Magnetometer Aligning the Particles 413 𝑝𝑚 𝐴 <𝑑 33 <826 𝑝𝑚 𝐴

Practical Applications Vibration Wireless Sensor Energy Harvesting

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