Gelatin Methacryloyl‐Based Tactile Sensors for Medical Wearables

Abstract

Gelatin methacryloyl (GelMA) is a widely used hydrogel with skin-derived gelatin acting as the main constituent. However, GelMA has not been used in the development of wearable biosensors, which are emerging devices that enable personalized healthcare monitoring. This work highlights the potential of GelMA for wearable biosensing applications by demonstrating a fully solution-processable and transparent capacitive tactile sensor with microstructured GelMA as the core dielectric layer. A robust chemical bonding and a reliable encapsulation approach are introduced to overcome detachment and water-evaporation issues in hydrogel biosensors. The resultant GelMA tactile sensor shows a highpressure sensitivity of 0.19 kPa −1 and one order of magnitude lower limit of detection (0.1 Pa) compared to previous hydrogel pressure sensors owing to its excellent mechanical and electrical properties (dielectric constant). Furthermore, it shows durability up to 3000 test cycles because of tough chemical bonding, and long-term stability of 3 days due to the inclusion of an encapsulation layer, which prevents water evaporation (80% water content). Successful monitoring of various human physiological and motion signals demonstrates the potential of these GelMA tactile sensors for wearable biosensing applications.

Facilely constructed two-sided microstructure interfaces between electrodes and cellulose paper active layer: eco-friendly, low-cost and high-performance piezoresistive sensor

“…In the detail enlarged view (Fig. 6c), two clearly obvious peaks P1 (systolic peak) and P2 (diastolic peak) can be clearly distinguished, which is similar to previous reports (Choong et al 2014;Li et al 2020b;Tian et al 2020). By attaching the sensor to the larynx, it can be used to recognize different words (Fig.…”

Binder-free printed PEDOT wearable sensors on everyday fabrics using oxidative chemical vapor deposition

“…Response and recovery times of 260 and 30 ms, respectively, were recorded while applying and releasing an approximate pressure of 1.8 kPa. It should be noted that the performance of oCVD PEDOT sensors is comparable to previously reported resistive devices based on conductive polymers (table S1) (34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47), even without any additives or sophisticated device structure in our sensors.…”

Highly Sensitive Flexible Tactile Sensors in Wide Sensing Range Enabled by Hierarchical Topography of Biaxially Strained and Capillary‐Densified Carbon Nanotube Bundles

“…Recently, flexible tactile sensors have been gaining attention for various applications, such as wearable haptic devices, health‐monitoring devices, and human–machine interfaces. [ 1–8 ] For practical application, flexible tactile sensors should have a high sensitivity (>1 kPa −1 ) over a wide sensing range (>10 kPa), [ 9–11 ] simultaneously prepared with low‐cost and scalable fabrications over a large area. [ 12,13 ] To satisfy these strict requirements, various sensing principles, which measure the change in electrical signals such as resistance (contact [ 14 ] /piezo [ 15 ] ‐resistivity), voltage (piezoelectricity [ 16 ] /triboelectricity [ 17 ] ), and capacitance, [ 18,19 ] have been introduced.…”