Autonomous Sensor Capsule for Usage in Bioreactors

Abstract

An autonomous biochemical sensor capsule for the remote monitoring of an algae culture cultivated in a photobioreactor is presented. The encapsulated system has a spherical shape with a diameter of 44 mm. Radio communication with a carrier frequency of 433 MHz is used to transfer the acquired sensor data in the bioreactor to a base station outside. Experiments with the first prototype inside the bioreactor filled with nutrient solution were performed to determine the reliability of the communication link. The packet error rate converged to 26% and the path loss on average was 96 dB. The functionality of the signal processing chain of acquired biochemical sensor values was evaluated using an experimental setup. Our second capsule prototype with potentiometric sensors demonstrates the pH-measurements of different buffer solutions dropped on the sensor electrodes with a pipette.

Technology modules from micro‐ and nano‐electronics for the life sciences

“…The outer diameter of the sensor capsule was set to 44 mm, which is a little smaller than the inner diameter of the reactor tubes . The system PCB is mounted in the equatorial plane of the capsule with its upper layer exposing the sensor surfaces, while the other components of the electrical circuit were installed on the opposite side.…”

“…Figure schematically depicts the PCB layout, where also the electrode surface for conductivity measurements can be recognized. In this example, the transceiver CC1101 is used as radio chip operating in the 433 MHz band …”

“…The outer diameter of the sensor capsule was set to 44 mm, which is a little smaller than the inner diameter of the reactor tubes. 85 The system PCB is mounted in the equatorial plane of the capsule with its upper layer exposing the sensor surfaces, while the other components of the electrical circuit were installed on the opposite side. The upper sphere of the capsule is permeable to the algae medium, while the lower part is hermetically sealed as is the PCB such that the liquid medium cannot enter the electronicscarrying side.…”

“…(c) photographs of both sides of the PCB: with microcontroller and transceiver (left)and sensor field (right). The semi-sphere above the sensor field is permeable to the cultivation broth, while the opposite side is impermeable as is the PCB layer 85.…”

Multi-Sensor Chip for Monitoring Key Parameters in Bioprocesses

“…This real-time method is highly desirable because of various advantages such as detecting small, local changes rapidly, adjusting relevant parameters, and maintaining the process at optimum condition [1]. Although such platforms have been demonstrated for bioprocesses monitoring [1], [7], [18]- [20], research on the subject has only been carried out for a small number of sensing modalities; no single work demonstrating the integration of six important process parameters on a single chip exists.…”