Search for: All records

Abstract Swallowing is an ensemble of voluntary and autonomic processes key to maintaining our body’s homeostatic balance. Abnormal swallowing (dysphagia) can cause dehydration, malnutrition, aspiration pneumonia, weight loss, anxiety, or even mortality—especially in older adults—by airway obstruction. To prevent or mitigate these outcomes, it is imperative to regularly assess swallowing ability in those who are at risk of developing dysphagia and those already diagnosed with it. However, current diagnostic tools such as endoscopy, manometry, and videofluoroscopy require access to clinical experts to interpret the results. These results are often sampled from a limited examination timeframe of swallowing activity in a controlled environment. Additionally, there is some risk of periprocedural complications associated with these methods. In contrast, the field of epidermal sensors is finding non-invasive and minimally obtrusive ways to examine swallowing function and dysfunction. In this review, we summarize the current state of wearable devices that are aimed at monitoring swallowing function and detecting its abnormalities. We pay particular attention to the materials and design parameters that enable their operation. We examine a compilation of both proof-of-concept studies (which focus mainly on the engineering of the device) and studies whose aims are biomedical (which may involve larger cohorts of subjects, including patients). Furthermore, we briefly discuss the methods of signal acquisition and device assessment in relevant wearable sensors. Finally, we examine the need to increase adherence and engagement of patients with such devices and discuss enhancements to the design of such epidermal sensors that may encourage greater enthusiasm for at-home and long-term monitoring. 

Electrotactile stimulus is a form of sensory substitution in which an electrical signal is perceived as a mechanical sensation. The electrotactile effect could, in principle, recapitulate a range of tactile experience by selective activation of nerve endings. However, the method has been plagued by inconsistency, galvanic reactions, pain and desensitization, and unwanted stimulation of nontactile nerves. Here, we describe how a soft conductive block copolymer, a stretchable layout, and concentric electrodes, along with psychophysical thresholding, can circumvent these shortcomings. These purpose-designed materials, device layouts, and calibration techniques make it possible to generate accurate and reproducible sensations across a cohort of 10 human participants and to do so at ultralow currents (≥6 microamperes) without pain or desensitization. This material, form factor, and psychophysical approach could be useful for haptic devices and as a tool for activation of the peripheral nervous system. 

Abstract Durable and conductive interfaces that enable chronic and high‐resolution recording of neural activity are essential for understanding and treating neurodegenerative disorders. These chronic implants require long‐term stability and small contact areas. Consequently, they are often coated with a blend of conductive polymers and are crosslinked to enhance durability despite the potentially deleterious effect of crosslinking on the mechanical and electrical properties. Here the grafting of the poly(3,4 ethylenedioxythiophene) scaffold, poly(styrenesulfonate)‐b‐poly(poly(ethylene glycol) methyl ether methacrylate block copolymer brush to gold, in a controlled and tunable manner, by surface‐initiated atom‐transfer radical polymerization (SI‐ATRP) is described. This “block‐brush” provides high volumetric capacitance (120 F cm^─3), strong adhesion to the metal (4 h ultrasonication), improved surface hydrophilicity, and stability against 10 000 charge–discharge voltage sweeps on a multiarray neural electrode. In addition, the block‐brush film showed 33% improved stability against current pulsing. This approach can open numerous avenues for exploring specialized polymer brushes for bioelectronics research and application.