Battery-Free, Stretchable, and Autonomous Smart Packaging

Abstract

In the food industry, innovative packaging solutions are increasingly important for reducing food waste and contributing to global sustainability efforts. However, current food packaging is generally passive and unable to adapt to changes in the food environment in real time. To address this, a battery-less and autonomous smart packaging system is developed that wirelessly powers closed-loop sensing and release of active compounds. This system integrates a gas sensor for real-time food monitoring, a Near-Field Communication (NFC) antenna, and a controlled release of active compounds to prevent quality deterioration in the complex food environment. The ability of the developed smart packaging system is demonstrated, to continuously monitor the freshness of fish products and to trigger the release of active compounds when the food starts to spoil. The system is able to extend the shelf-life of the food product up to 14 days, due to the controlled release of antioxidant and antibacterial compounds. The system can pave the way toward an Internet of Things solution that addresses protection, active prevention of food spoilage, and sustainability, facing all the current challenges of the food packaging industry.

Keywords: NFC antenna; PNIPAM; intelligent packaging; smart materials.

Figure 1

Device concept. a) Schematic illustrating the exploded view of the complete hybrid, battery‐free system. b) Different parts of the smart packaging. c) Working mechanism of the smart packaging. d) Image illustrating the closed‐loop system.

Figure 2

a) Scanning electron microscopy (SEM) image of the spray‐coated SWCNTs on a silicon substrate. b) Response of CNTs gas sensor toward ammonia for concentrations ranging from 15 to 75 ppm with a step of 15 ppm, the blue zones represent the exposure zone followed by a recovery step via external heating. c) Response of CNTs gas sensor toward different concentrations of methane. d) Response of CNTs gas sensor toward different concentrations of carbon dioxide, e) Calibration curve of CNTs gas sensor toward ammonia. f) Selectivity test of CNTs gas sensor in the presence of 90 ppm ammonia, 500 ppm methane, and 7500 ppm carbon dioxide. g) Resistance change of the gas sensor in the presence of different ammonia concentrations ranging from 15 to 90 ppm with a step of 15 ppm without a recovery step. h) The response of the CNTs gas sensor toward ammonia without and with PDMS for 90 ppm of NH₃ to investigate the effect of PDMS on the response of the gas sensor. i) The effect of the mechanical stress “bending” on the performance of the CNTs gas sensor on PDMS substrate “in the presence of 90 ppm NH₃”.

Figure 3

a) An illustration of the NFC antenna with a chip. b) The resonance frequency and the gain of the fabricated antenna. c) The change in the resistance of the antenna coil under a mechanical strain in terms of stretching. d) The effect of mechanical stress in terms of stretching on the resonance frequency of the antenna. e) Bending effect on the resonance frequency of the antenna. f) The effect of temperature change on the resonance frequency of the antenna. g) The effect of humidity change on the resonance frequency of the antenna. h) Strain effect on the resistance of the electrodes, i) ANSYS mechanical simulation of the antenna under different mechanical stress.  Data are expressed as means ± SE.

Figure 4

a) An illustration of the final smart packaging composed of a gas sensor, NFC antenna, and active packaging. b) The experimental setup was used to investigate the effect of different gases on the gain and harvested voltage from the NFC antenna. c) The change in the gain of the antenna versus humidity ranging from 30% to 100% to simulate the food packaging environment. d) The change in the gain of the antenna versus temperature ranging from 5 to 25 °C to simulate the storage of the food packaging inside a fridge and at room temperature. e) The gain change of the NFC antenna in the presence of NH₃, CH₄, and CO₂ ranging from 5 to 40 ppm “ammonia”. f) The change in the harvested voltage in the presence of different NH₃ concentrations ranging from 5 ppm to 40 ppm. g) The change in harvested voltage versus the position inside the Helmholtz Coil. h) The change in Gain and the temperature (active packaging film) versus different concentrations of NH₃ ranging from 10 to 40 ppm.

Figure 5

a) The experimental setup used to investigate the performance of the smart packaging with a real sample ‐salmon‐, b) temperature and humidity change inside a box with salmon starting from closing the lid at t = 0 min, c) TVB‐N and NH3 increase inside the box over time, d) 2‐Butanone and 3‐methyl butanol change over time inside a box containing salmon and a powered‐smart packaging measured via GC‐MS, e) cinnamaldehyde, and eugenol change‐over‐time inside a box containing salmon and a powered‐smart packaging measured via GC‐MS, f) cumulative release of cinnamaldehyde, and eugenol over a period of 24 h inside a box containing salmon and a powered‐smart packaging measured via GC‐MS, g) TVB‐N increase at 4 °C with non‐powered “control” and powered smart packaging. Data are expressed as means ± SE; student t‐test for the 16 days point, ***p ≤ 0.001, ns‐not significant.