Wireless, Room Temperature Volatile Organic Compound Sensor Based on Polypyrrole Nanoparticle Immobilized Ultrahigh Frequency Radio Frequency Identification Tag

Abstract

Due to rapid advances in technology which have contributed to the development of portable equipment, highly sensitive and selective sensor technology is in demand. In particular, many approaches to the modification of wireless sensor systems have been studied. Wireless systems have many advantages, including unobtrusive installation, high nodal densities, low cost, and potential commercial applications. In this study, we fabricated radio frequency identification (RFID)-based wireless sensor systems using carboxyl group functionalized polypyrrole (C-PPy) nanoparticles (NPs). The C-PPy NPs were synthesized via chemical oxidation copolymerization, and then their electrical and chemical properties were characterized by a variety of methods. The sensor system was composed of an RFID reader antenna and a sensor tag made from a commercially available ultrahigh frequency RFID tag coated with C-PPy NPs. The C-PPy NPs were covalently bonded to the tag to form a passive sensor. This type of sensor can be produced at a very low cost and exhibits ultrahigh sensitivity to ammonia, detecting concentrations as low as 0.1 ppm. These sensors operated wirelessly and maintained their sensing performance as they were deformed by bending and twisting. Due to their flexibility, these sensors may be used in wearable technologies for sensing gases.

Nanomaterial‐Enabled Wearable Sensors for Healthcare

“…In a CNT/poly(vinyl alcohol) (PVA) fiber based resistive sensors, high humidity level can swell the filament, decrease the intertube distance of CNTs and thus decrease the resistance of the CNT/PVA fibers. [55] To track the gas concentration for personal wellness and security surveillance, wearable gas sensors based on graphene, [32] rGO, [45,173] ZnO NPs, [174] AgNW-graphene, [175] CNT/SnO 2 NW hybrid film, [31] and polypyrrole NPs [176] were developed to detect the concentration of gases such as nitrogen dioxide (NO 2 ), [31,32,173] ammonia (NH 3 ), [176] hydrogen sulfide (H 2 S), [45] hydrogen (H 2 ), [45] ethanol (C 2 H 5 OH), [45,174] acetic acid (CH 3 COOH), [176] dimethyl methylphosphonate (C 3 H 9 O 3 P, DMMP), [175] acetone (CH 3 COCH 3 ), [175] methanol (CH 3 OH), [175] and tetradecane (C 14 H 30 ). [175] Increase or decrease in resistance is typically detected, depending on whether the gaseous stimulus is an electron donator or an electron acceptor.…”

“…CNT yarn/Ecoflex/ CNT yarn [54] Humidity Capacitive ΔC/C 0 : 0-0.025 for humidity of 48-70% 48-75% ---CNT/PVA [55] Humidity Resistive ΔR/R 0 : 0-20 for humidity of 60-100% 60-100% -160% -Polypyrrole NP [176] CH 3 However, different functions may affect each other, especially when multistimuli are coexisting. For instance, in a capacitive sensor, multiple stimuli can cause capacitance change, including tensile stretching (capacitance increase), normal pressure (capacitance increase), finger approaching (capacitance decrease), and humidity level change (capacitance increase or decrease).…”

“…Wireless transmission capability can be enabled by integrating an antenna [169,175,176] or a Bluetooth module. [42,45,119,175] Flexible gas sensors was connected to a passive RFID to enable wireless detection of NH 3 and acetic acid.…”

“…[42,45,119,175] Flexible gas sensors was connected to a passive RFID to enable wireless detection of NH 3 and acetic acid. [176] The passive feature of the RFID eliminates the need for on-system power supply. In another example, a supercapacitor array connected with a RF power receiver was incorporated into a sensor system containing a strain sensor and a UV/NO 2 sensor to realize a stretchable (50%) and wirelessly rechargeable sensor system.…”

Recent progress on nanostructured conducting polymers and composites: synthesis, application and future aspects

“…In most of flexible devices, the resistance remains almost unchanged and the sensing performance was not affected during repetitive bending cycles, which demonstrated mechanical stability indicating the potential for soft/wearable electronic technology [298]. Jun et al [299] fabricated novel radio frequency identification (RFID)-based wireless sensor systems using carboxyl group functionalized PPy (C-PPy) nanoparticles (NPs). The C-PPy nanoparticles with an average size of 60 nm, were synthesized from a water-soluble polymer and highly monodispersed metal cations.…”