A Novel Spray-On Sensing Platform Technology that Enables Wearable Visual Monitoring of Physiological Data and Environmental Exposure

Abstract Wearable sensing has the potential to transform health care by alerting users about important information regarding their health and potential exposure to environmental risks. Some of the most critical barriers to wearable sensing include the cost, complexity, and reliability. Addressing the first two challenges is particularly

important to prevent exacerbation of a digital divide in health between those who have access to technologies and the digital literacy to work them and those that do not. A widely deployable sensing platform technology for improving health and wellness that can equitably reach the population is thus needed. Past successes in point-

of-care and at-home sensing, including lateral flow sensors, have demonstrated that simple, robust designs that are customizable to different targets can provide significant value and high reliability without the need for electronic systems. With that motivation, we are developing a spray-on sensor technology to serve as a platform

for custom wearable coatings that can be easily interpreted by a color change upon exposure to tailored target stimuli. Our encouraging results recently demonstrated a set of proof-of-concept spray-on sensors formulated with diacetylene-containing amphiphiles that could detect physical stimuli (UV radiation) and different chemical

targets depending on the amphiphile head-group chemistry. In the proposed project, we are initiating an iterative development approach to understand and enhance the safety and efficacy of our spray-on sensing formulations. In Aim 1, we will focus our efforts on assessing and improving the mechanical properties of our spray-on coating

formulations for improved resistance to abrasion and washing without impacting their target sensitivity. Success of this aim will result in a robust coating that can provided reliable sensing throughout conditions experience in routine daily use. In order to provide an understanding of the biocompatibility of distinct formulations that are to

be applied directly to the skin for sweat analysis, in Aim 2 we will conduct multiple complementary tests for skin irritation, permeation, and induction of adverse outcome pathways of skin sensitization. Through this aim we will be able to effectively make risk assessments in order to define appropriate exposure limits and if necessary

utilize alternative formulation strategies for any components of concern. In Aim 3 with the dual intention of demonstrating the efficacy and reliability of our spray-on approach for different sensing applications, we will examine distinct spray-on formulations with tailored functional head-group chemistry of the diacetylene-

amphiphiles for implementation of sweat analysis for lead poisoning, breath analysis for acetone (ketosis), and UV exposure for radiation dosimetry. These three sensor formulations will operate by applying the distinct spray coating onto the skin, onto a surgical mask, or onto fabric (clothing), respectively. By tuning the sensitivity,

dynamic range, and selectivity of the individual spray-on sensor formulations for their specified target of interest, these studies will establish this as a novel platform technology for generating spray-on wearable coatings that are capable of reliably monitoring information important to understanding health and environmental exposure.