Tunable Capacitive Pressure Sensors Enabled By Printed Microstructures and Designed using Continuum Mechanics Modeling
Abstract
Abstract (approved for public release)Blast overpressure events account for a significant portion of head injuries among service mem bers. Detecting these events in real-time is critical to mitigate this problem. The challenge, however, is that the blast overpressu re presents as a high-speed wave. Therefore, a possible sensing scheme must have a high temporal resolution, along with a high overa ll sensing range. Additionally, the event is directional, and to be fully resolved must be sensed with distributed sensors at varyin g locations. Flexible hybrid electronics (FHE) offers the ability to fabricate large-area distributed sensors at an appropriate cost for scaling, while also offering a form-factor appropriate for wearable technology. To date, flexible hybrid pressure sensors do no t offer the appropriate temporal resolution, as they rely on the deformation of an elastomeric material. Relying directly on the ela stomer presents a tradeoff -- the material must deform in response to a force for sensitivity, but the temporal response will be pro portionally related to the stiffness of the deformable material. To combat this tradeoff, we propose to utilize 3D-printed elastomer ic microstructures as the deformable elements within a capacitance-proximity transducer. This will allow for a printable, large-area sensing system with the appropriate response to high-speed pressure waves. To accomplish the work, we will first analyze the mechan ical properties of varied elastomeric microstructures using finite element analysis. In parallel, we will model cross-capacitance tr ansducers to optimize the overlap between the modifiable electric field and the elastomeric microstructures. The modeling efforts wi ll culminate in a time-resolved multi-physics simulation to understand the temporal response of the sensing scheme. Next, we will ex perimentally validate the model by printing the sensors using a combination of two additive printing techniques. The transducer will consist of electronically active nanomaterial thin films printed through aerosol jet printing. The elastomeric microstructures will be printed using a high-resolution 3D printer. The optimized sensor design, obtained through the modeling efforts, will be fabricat ed and tested at various loads and loading times to validate the proposed sensing scheme. The final outcome of the project will be a wearable sensor that can be fabricated over large areas to enable distributed sensing of blast pressure events.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2021
- Source ID
- N000142112851
Entities
People
- Joseph B Andrews
Organizations
- Office of Naval Research
- United States Navy
- University of Wisconsin System