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Division of Energy and Innovation

Subsea Systems Institute (SSI)

Sensors Based on Organic Electrochemical Transistors (OECTs) for Deep Sea Leakage and Chemical Detection

Status: AWARD END DATE: 08/31/22

Background:

Pipeline networks are the most efficient method to transport oil, gas, and other liquids, but leaks are common and oftentimes go undetected. Leaks can result in billions of dollars of property damage, represent significant losses of revenue, and present significant safety challenges. Pipeline networks rely on a Supervisory Control And Data Acquisition (SCADA) system to monitor changes in pressure, flowrate, and other pipeline characteristics3 along with a Computational Pipeline Monitoring System (CPM) to analyze the data and detect leaks. However, a recent study found that the CPM could only identify 19 % of pipeline leaks. These failures include large leaks, especially for complex pipeline networks with multiple entry points.

Industry Impact:

The novelty of the work is in the development of a new, low-cost, wireless sensor for selective chemical detection in deep sea environments. Prior work has not explored the combination of organic electrochemical transistors (OECTs) or thin film transistors (TFTs) with molecularly imprinted polymers (MIPs) for selective chemical sensing or the development and testing of OECTs and TFTs in seawater. The results of this work will demonstrate a proof-of-principle of versatile, low-cost sensors that can aid in the early detection for leak and spillage detection.

schematic image
Figure 1: Schematic for an organic electrochemical transistor with an MIP layer shown in purple, a proposed sensor array, and sensors in a distributed pipeline network, which can respond to leaks and spills in the vicinity of the sensor

Altogether, this work will demonstrate a novel platform for continuous, real-time monitoring of chemicals and contaminants underwater. This will enable more rapid detection of leaks and contaminants during deep sea operations. Furthermore, the sensors proposed are compact and easy to fabricate, resulting in low-cost devices that can be fabricated to scale and replaced when necessary.

Project Goals:

To address the failure of CPM to identify leaks, we will develop a precise and sensitive amperometric sensor platform based on molecular-level recognition by molecularly imprinted polymers (MIPs) and electronic transduction through organic thin film transistors (TFTs) and organic electrochemical transistors (OECTs). We will build a sophisticated real-time sensor for chemical binding events that can be used to detect the presence of specific chemicals in the aqueous environment. In the proposed research, we plan to create and use a modified electrochemical sensor model to investigate the performance of sensors at low temperatures and subsea conditions.

Tasks:

  1. Design and testing of MIP layers
  2. Fabrication and testing of OECTs and TFTs
  3. Integrate OECTs and TFTs with MIPs and analyze response to target chemicals
  4. Test integrated sensors in the presence of interfering species
  5. Develop a model for the response of OECTs and TFTs

Gantt Chart:

sensors-based-organic-electrochemical-transistors-gantt.png

Significant Findings: