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.
