Highly Stretchable Starch Hydrogel Wearable Patch for Electrooculographic Signal Detection and Human–Machine Interaction

Abstract

It is crucial to prepare wearable devices with high stretchability to reduce the mechanical mismatch when attached to the skin. Recently, pure polysaccharide‐based hydrogels have been intensively focused on due to the living matter‐like softness, abundance, inherent biocompatibility, complete biodegradability, and renewability. However, it remains a significant challenge to achieve pure polysaccharide‐based hydrogels with high stretchability. Herein, a facile strategy is presented to synthesize a highly stretchable hydrogel wearable patch by integrating the starch (from lotus rhizome) as skeleton and sodium chloride as the electrolyte, exhibiting several advantages such as low modulus (≈4.4 kPa), broad stretching range (0≈790%), high ionic conductivity (10 S m−1), high linearity (0.996, 0≈300%), and good reproducibility (>1000 cycles). Surprisingly, both stretchability and softness have surpassed those of other pure polysaccharide‐based hydrogels reported in the literature. Furthermore, the combination of the adhesion, the low modulus, and stretchability can realize conformal attachment to different kinds of uneven objects, including the skin. Based on these properties, an electrooculographic (EOG) signal acquisition system and a relevant prototype video game using starch hydrogel patches are designed, exhibiting great potential in EOG signals monitoring as well as human–machine interaction. Moreover, other functions such as biocompatibility and biodegradability are demonstrated.

Biodegradable Polymer Composites for Electrophysiological Signal Sensing

“…The biodegradability of a polymer is primarily due to the principle of releasing polymer-binding chains through various microorganisms, water, and biofluids. In addition, naturally extractable guar gum [ 18 ], gelatin [ 118 ], starch [ 119 ], and fabric [ 120 , 121 ] have been adopted for achieving green electrophysiological devices, by fabricating biodegradable polymers. Furthermore, research is underway to improve parameters such as the conductivity, biocompatibility, and stability of biodegradable polymers.…”

“…The biodegradability of a polymer is primarily due to the principle of releasing polymer-binding chains through various microorganisms, water, and biofluids. In addition, naturally extractable guar gum [18], gelatin [118], starch [119], and fabric [120,121] have been adopted for achieving green (d) EEG waveform of alpha and beta waves (adapted from [115] with permission from John Wiley and Sons); (e) swelling rate and degradation rate of conduct polymer coatings (adapted from [116] with permission from the Elsevier B.V.).…”

“…The biodegradability of a polymer is primarily due to the principle of releasing polymer-binding chains through various microorganisms, water, and biofluids. In addition, naturally extractable guar gum [18], gelatin [118], starch [119],…”

Advances in Materials, Sensors, and Integrated Systems for Monitoring Eye Movements

“…Due to the development of these technologies and 3D printing, designing wearable platforms has become possible, such as eyeglass types [ 5 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ], face mask types [ 7 , 40 , 41 , 42 ], ear plug types [ 43 , 44 , 45 , 46 , 47 ], and headband types [ 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ] for various applications. Previously, various controllers for an HMI such as wheelchairs [ 1 , 4 , 51 , 52 ], drones [ 11 , 59 ], game interfaces [ 5 , 36 , 47 , 60 , 61 ], and virtual keyboards [ 34 , 38 , 51 , 62 ] were created by using only an EOG signal. Recently, various healthcare monitoring systems [ 7 , 40 , 41 ,…”

Fully Fibrous Large‐Area Tailorable Triboelectric Nanogenerator Based on Solution Blow Spinning Technology for Energy Harvesting and Self‐Powered Sensing

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Up to now, tactile sensors have made significant breakthroughs with novel features such as stretchable, [5][6][7] self-healing, [8,9] self-powered, [10,11] and multi-functional properties. [12][13][14] Most of these tactile sensors must require battery storage to provide energy if they continuously collect information.

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