FHE Device Encapsulation and Overmold: Application-Responsive Encapsulation Processes for FHE Devices

NextFlex roadmap anticipates that Flexible Hybrid Electronics (FHE) encapsulation will require application-specific solutions to maintain FHE-specific advantages (particularly flexible and slim form factor). This presentation describes a broad range of solutions by demonstrating a methodology of differentiated encapsulation approaches in response to three FHE devices. Encapsulation solutions were enacted for each case selected for this project: the (1) AFRL-originated NextFlex Arduino device, (2) a structural asset monitoring device from Acellent, and (3) a MIL-810G-compliant digital microcontroller / RF circuit from Lockheed-Martin (LM) and Binghamton University (BU). In order to achieve the goals, commercially mature encapsulation materials with scalability were identified, allowing us to reach TRL/MRL 7/7 and 6/6 for use case 1 and use cases 2 and 3, respectively. For case 1, the AFRL-originated NextFlex Arduino device, a compression molding process was developed using Eastman's Extent co-polyester film. Experiments were conducted to optimize the process required for encapsulation. Once these were established, live Arduino devices were encapsulated using the process. These successfully encapsulated live devices were sent back to Nextflex for evaluation. The results showed that a vast majority (~72 %) of the encapsulated devices were functional after the encapsulation process, validating our approach. For case 2, the structural asset monitoring device from Acellent, a spray coating of a superhydrophobic durable coating was successfully optimized using an acrylic based polymer. Live devices were coated and sent to Acellent for testing. For case 3, the same acrylic coating from case 2 was coated onto live devices, which was sent to LM for testing. In both cases, all the coated devices were fully functional after the encapsulation, validating our approach. As a result of this work, the creation of a generic methodology for the selection of encapsulation approaches developed which will significantly enable the rapid development of FHE devices in the future.