Self-Powered Flexible Sour Sensor for Detecting Ascorbic Acid Concentration Based on Triboelectrification/Enzymatic-Reaction Coupling Effect

Abstract

Artificial sensory substitution systems can mimic human sensory organs through replacing the sensing process of a defective sensory receptor and transmitting the sensing signal into the nervous system. Here, we report a self-powered flexible gustation sour sensor for detecting ascorbic acid concentration. The material system comprises of Na2C2O4-Ppy with AAO modification, PDMS and Cu wire mesh. The working mechanism is contributed to the triboelectrification/enzymatic-reaction coupling effect, and the device can collect weak energy from body movements and directly output triboelectric current without any external power-units. The triboelectric output is affected by AA concentration, and the response is up to 34.82% against 15.625 mM/L of AA solution. Furthermore, a practical application in detecting ascorbic acid concentration of different drinks has been demonstrated. This work can encourage the development of wearable flexible electronics and this self-powered sour sensor has the potential that can be acted as a kind of gustatory receptors to build electronic tongues.

Biomimetic Wearable Sensors: Emerging Combination of Intelligence and Electronics

“…The hydrogel-based flexible electronic tongues developed by Yeom et al [158a] and Lin et al [162] utilized different electrical signals produced by chemical bonding between the target compound and polymer network when in contact to determine the contents of quinine sulfate and polyphenolics, which can reflect bitter and astringent tastes (Figure 13d). Zhao et al [163] and Xue et al [164] synthesized wearable biomimetic taste sensors with high selectivities and abilities to respond to ascorbic acid and alcohol based on coupled enzymatic-triboelectric and enzymatic-piezoelectric reactions, respectively. The enzymatic reaction is activated when the target analyte is detected, increasing charge separation and enhancement of the triboelectric/piezoelectric effect, leading to a higher output signal.…”

“…Zhao et al. [ 163 ] and Xue et al. [ 164 ] synthesized wearable biomimetic taste sensors with high selectivities and abilities to respond to ascorbic acid and alcohol based on coupled enzymatic‐triboelectric and enzymatic‐piezoelectric reactions, respectively.…”

Advances in Smart Sensing and Medical Electronics by Self-Powered Sensors Based on Triboelectric Nanogenerators

“…Furthermore, this self-powered wearable ion conductance TDD system can be driven and adjusted by the energy obtained by biomechanical motion for closed-loop motion detection and treatment. Zhao et al [127] developed a self-powered flexible acid taste sensor based on frictional electrification/enzyme-reaction coupling (Figure 7d) to detect ascorbic acid concentration. This sensor can collect energy from human movement and thus eliminates the need for an external power supply.…”

Molecular engineering‐device efficiency relation: Performance boosting of triboelectric nanogenerator through doping of small molecules

“…When there is a separation of surfaces, one material tends to retain more electrons while another one tends to give off. 5,6 This situation results in the formation of triboelectric charges. [7][8][9][10][11] When dielectric materials are in contact or separated, the charges are in balance and no current flows are taken place toward conductor layers.…”

“…Principally, this phenomenon requires the formation of bonds due to the chemical adhesion of two surfaces and leads to charge movement between two materials to equalize their electrochemical potentials. When there is a separation of surfaces, one material tends to retain more electrons while another one tends to give off 5,6 . This situation results in the formation of triboelectric charges 7‐11 .…”