MA - Development of an Embedded PEDOT:PSS Microchannel-Based Whisker Sensor for water flow Detection (A3-SP 1)
Abstract
This thesis investigates the design, fabrication, and preliminary characterization of a biomimetic whisker-based sensing system utilizing embedded PEDOT:PSS (a widely studied organic conductive polymer) microchannel strain sensors. The proposed concept integrates two orthogonally arranged flexible microchannel sensors within the follicle region of a straight whisker structure to enable two-dimensional (X/Y) bending detection. Each whisker is fabricated using a room-temperature curing epoxy (e.g., Epoxy 0030), while the sensing elements are realized as separate flat microchannel-based strain sensors (PDMS or epoxy-based), subsequently embedded into the whisker during casting. The sensors are positioned near the outer radius of the follicle region (approximately 60–70% of the radius) to maximize strain sensitivity while maintaining structural integrity. The thesis focuses on fabrication methodology, material compatibility, and initial performance evaluation. Key investigations include PEDOT:PSS channel formation via multiple filling cycles or additive-enhanced formulations, integration strategies for embedded sensing elements, and basic electromechanical testing. A small array of 6–8 whisker sensors will be fabricated to assess repeatability and manufacturability. After the successful completion of this thesis, advanced characterization, including sensitivity, linearity, hysteresis, and drift, will be conducted in a subsequent phase within the IMEK research group using a dedicated readout circuit and test stand. The outcomes of this work are expected to contribute to the development of robust, scalable whisker-inspired tactile sensing systems for underwater robotic navigation applications (in collaboration with the MUM department, TUHH) as well as flow sensing applications.
Detailed Task description
o Design and Concept Development (with IMEK support)
Define whisker geometry (straight profile, ~5 cm length, tapered structure)
Design follicle region (~2 cm base diameter) with embedded sensor cavities
Design two orthogonal microchannel sensor strips (X/Y alignment)
Define channel placement at mid-to-outer radius (~60–70%)
Develop CAD models for whisker and sensor integration
o Fabrication of Microchannel Sensor Plates
Fabricate flat flexible microchannel sensors (PDMS or epoxy-based)
Implement sacrificial wire or molding techniques for channel formation
Optimize PEDOT:PSS filling process:
multiple filling cycles and drying under vacuum oven
optional additive modification (e.g., DMSO, ethylene glycol)
optimization of PEDOT:PSS concentration
Integrate electrical contacts using:
silver epoxy
or base reservoir approach
o Integration into Whisker Structure (with IMEK support)
Develop molding strategy for embedding sensor plates into whisker follicle
Cast whiskers using epoxy 0030 (room-temperature curing)
Ensure proper alignment of orthogonal sensors (X/Y)
Implement wiring and sealing strategy for embedded electrodes
Fabricate 6–8 whisker sensor prototypes
o Preliminary Sensor Characterization (with IMEK support)
Conduct the following tests on standalone sensor plates and embedded sensors:
PEDOT:PSS filling uniformity test
Temperature dependence test
Frequency response test (dynamic resistance monitoring during cyclic loading)
Small-strain resolution test
Large deformation limit test
o Comparative Evaluation
Compare performance between:
standalone sensor plates
embedded whisker sensors
Evaluate:
signal consistency
qualitative sensitivity trends
fabrication repeatability across multiple samples
o Documentation and Analysis
Write a scientific report and simulator instruction manual
Project Start: As soon as possible
Project Duration: 6 months
Contact Person:
Contact Person ----- Supervisor: emin.istif@tuhh.de, Co-Supervisor: Mohammad.sadeghi@tuhh.de