Printed Multifunctional Laminates: Additively Manufactured Sensors Integrated with Ultra-High Molecular Weight Polyethylene Ballistic Resistant Materials

Additive Manufacturing (AM) has the potential to enable unique opportunities for placement, form-factor, and functionality of sensing elements through the use of nontraditional substrates. Most of these substrates are primarily utilized for mechanical applications such as ballistic protection. As conformal/hybrid AM fabrication techniques advance, it has become possible to integrate electrical and/or communication technology directly onto the material, increasing overall utility. In this work, an RF sensing circuit is integrated with an ultra-high molecular weight polyethylene (UHMWPE) fiber laminate, a ballistic resistant material. The direct-write, AM circuit, enables the detection of frequency bands in the C-band utilizing a printed antenna, an RF detection circuit, capacitor networks, and printed impedance matching elements. This work demonstrates that one can overcome challenges including unknown RF properties, substrate thicknesses, poor printed adhesion, and increased/variable surface roughness. As such, we present an RF detection system integrated with an UHMWPE substrate verified in both the laboratory and utilizing Ansys HFSS simulations. The resulting RF system demonstrates full functionality as well as the potential to be integrated with microcontroller technology, additional sensors, and LED indicators all powered through a commercial off-the-shelf battery.