Precision wearable accelerometer contact microphones for longitudinal monitoring of mechano-acoustic cardiopulmonary signals.

Mechano-acoustic signals emanating from the heart and lungs contain valuable information about the cardiopulmonary system. Unobtrusive wearable sensors capable of monitoring these signals longitudinally can detect early pathological signatures and titrate care accordingly. Here, we present a wearable, hermetically-sealed high-precision vibration sensor that combines the characteristics of an accelerometer and a contact microphone to acquire wideband mechano-acoustic physiological signals, and enable simultaneous monitoring of multiple health factors associated with the cardiopulmonary system including heart and respiratory rate, heart sounds, lung sounds, and body motion and position of an individual.

Conformal Antireflective Surface Formed onto 3-D Silicon Structure.

This letter reports on the fabrication, simulation and characterization of conformal antireflective black-silicon (BSi) nanowires on a 3D silicon structure. The BSi nanostructures were formed on various facets of a 3D Si structure including sharp tips and sidewalls using a metal-assisted chemical (MAC) etching process. The conformal BSi design was simulated using FDTD Lumerical software.

Micro-Fresnel-Zone-Plate Array on Flexible Substrate for Large Field-of-View and Focus Scanning.

Field of view and accommodative focus are two fundamental attributes of many imaging systems, ranging from human eyes to microscopes. Here, we present arrays of Fresnel zone plates fabricated on a flexible substrate, which allows for the adjustment of both the field of view and optical focus. Such zone plates function as compact and lightweight microlenses and are fabricated using silicon nanowires.