(Invited) Point-of-Use Flexible Sensors for Health and Environmental Applications: Assessment of Motor Skills and Chemical Exposure

Abstract

Rapid, on-site assessment is highly desirable in the fields of both medical treatment and novel robotics. To achieve this goal, our research aims to develop low-cost, flexible, large-area sensor devices for different health and environmental applications. In this presentation, we discuss case studies using similar pressure sensors for two different point-of-use applications: Autism spectrum disorder (ASD) motor skills characterization. There is no objective metric for evaluating motor skill training progress in autistic children, and current assessments rely on qualitative surveys. A common method used is a finger tapping test that requires videotaping and unreliable, time-consuming manual analysis, with large room for errors, even with computer vision analysis algorithms. We have fabricated an instrumented glove with touch sensors on textile for straightforward finger tapping patterns characterization. The results provide immediate objective feedback not only on the tapping counts, but on the temporal data (such as tapping duration and variation in duration) as well, which was not collected before. For the index finger tapping test, children with ASD perform less counts per minute compare to typically developing (TD) children. In addition, children with ASD tap their finger for an average longer duration, with larger variation between tap durations. In a 4 fingers tapping test children with ASD tend to have more irregular patterns and skip fingers compared to TD children. This glove could find future use for characterizing motor skills of people suffering from Parkinson’s disease, epilepsy seizures, and other neurological motor disorders. Robotic sensors for simultaneous pressure and organophosphate (OP) pesticide detection. There is an urgent need of sensor technologies to monitor hazardous materials for security and environmental applications. In particular, the occurrence of OP pesticide residues in agricultural products that poses a serious concern in the food and agriculture industries. Hence, rapid on-site detection of OPs through remote robotic sampling is highly desired to avoid placing people at exposure risks. To handle sample collection, the robotic manipulator requires tactile feedback, in order to ensure no damage will be done to either the robot or the other object in contact due to excessive force. To provide tactile feedback, pressure sensors based on capacitive mechanism were chosen. The sensitivity of the capacitive pressure sensors was tuned by adjusting the dielectric compressibility. Particularly, the sensitivity was increased by choosing softer materials, e. elastomers with low elastic modulus and porous structure that further lower elastic moduli of the foam dielectrics compared to solid films of the same material. We have combined low-cost chemical and pressure sensors together on disposable gloves, and demonstrated successive simultaneous tactile sensing and OP pesticide detection in a point-of-use platform that is scalable and economical.