Secure and Stable Wireless Communication for an Ingestible Device.

Wireless communication enables an ingestible device to send sensor information and support external on-demand operation while in the gastrointestinal (GI) tract. However, it is challenging to maintain stable wireless communication with an ingestible device that travels inside the dynamic GI environment as this environment easily detunes the antenna and decreases the antenna gain. In this paper, we propose an air-gap based antenna solution to stabilize the antenna gain inside this dynamic environment. By surrounding a chip antenna with 1 ~ 2 mms of air, the antenna is isolated from the environment, recovering its antenna gain and the received signal strength by 12 dB or more according to our in vitro and in vivo evaluation in swine. The air gap makes margin for the high path loss, enabling stable wireless communication at 2.4 GHz that allows users to easily access their ingestible devices by using mobile devices with Bluetooth Low Energy (BLE). On the other hand, the data sent or received over the wireless medium is vulnerable to being eavesdropped on by nearby devices other than authorized users. Therefore, we also propose a lightweight security protocol. The proposed protocol is implemented in low energy without compromising the security level thanks to the base protocol of symmetric challenge-response and Speck, the cipher that is optimized for software implementation.

Integrating biopolymer design with physical unclonable functions for anticounterfeiting and product traceability in agriculture.

Smallholder farmers and manufacturers in the Agri-Food sector face substantial challenges because of increasing circulation of counterfeit products (e.g., seeds), for which current countermeasures are implemented mainly at the secondary packaging level, and are generally vulnerable because of limited security guarantees. Here, by integrating biopolymer design with physical unclonable functions (PUFs), we propose a cryptographic protocol for seed authentication using biodegradable and miniaturized PUF tags made of silk microparticles. By simply drop casting a mixture of variant silk microparticles on a seed surface, tamper-evident PUF tags can be seamlessly fabricated on a variety of seeds, where the unclonability comes from the stochastic assembly of spectrally and visually distinct silk microparticles in the tag. Unique, reproducible, and unpredictable PUF codes are generated from both Raman mapping and microscopy imaging of the silk tags. Together, the proposed technology offers a highly secure solution for anticounterfeiting and product traceability in agriculture.

Prospective Evaluation of the Transparent, Elastomeric, Adaptable, Long-Lasting (TEAL) Respirator.

N95 filtering facepiece respirators (FFR) and surgical masks are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. However, currently available FFR's and masks have major limitations, including masking facial features, waste, and integrity after decontamination. In a multi-institutional trial, we evaluated a transparent, elastomeric, adaptable, long-lasting (TEAL) respirator to evaluate success of qualitative fit test with user experience and biometric evaluation of temperature, respiratory rate, and fit of respirator using a novel sensor. There was a 100% successful fit test among participants, with feedback demonstrating excellent or good fit (90% of participants), breathability (77.5%), and filter exchange (95%). Biometric testing demonstrated significant differences between exhalation and inhalation pressures among a poorly fitting respirator, well-fitting respirator, and the occlusion of one filter of the respirator. We have designed and evaluated a transparent elastomeric respirator and a novel biometric feedback system that could be implemented in the hospital setting.