Abdullah Bukhamsin, Khalil Moussi, Ran Tao, Gilles Lubineau, Ikram Blilou, Khaled Nabil Salama, Jurgen Kosel
Robust, Long-term and Exceptionally Sensitive Microneedle-based Bioimpedance Sensor for Precision Farming
Advanced Science (2021, accepted)
Precision farming has the potential to increase global food production capacity whilst minimizing traditional inputs. However, the adoption and impact of precision farming are contingent on the availability of sensors that can discern the state of crops, while not interfering with their growth. Electrical impedance spectroscopy offers an avenue for non- destructive monitoring of crops. To that end, we report on the deployment of impedimetric sensors utilizing microneedles that can be used to pierce the waxy exterior of plants to obtain sensitive impedance spectra in open-air settings with an average relative noise value of 3.83%. The sensors are fabricated using a novel micromolding and release method that is compatible with UV photo-curable and thermosetting polymers. Assessments of the quality of the MNs under scanning electron microscopy show that the replication process is high in fidelity to the original design of the master mold and that it can be used for upwards of 20 replication cycles. The sensor’s performance is validated against conventional planar sensors for obtaining the impedance values of Arabidopsis thaliana. As we were able to detect a change in impedance due to lighting and hydration, this raises the possibility for their wide- spread use in precision farming.
micromolding, microneedles, impedance biosensor, precision farming, smart farm