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The objective of any cell culturing platform is to decipher the in vivo functionality of native tissue in order to deliver reliable cell models for disease and pharmacological studies and eventually in patient-specific tissue engineering. We present a new perspective in lab-on-chip implementations for cell culturing, emphasizing on a versatile technology for cell micropatterning that can integrate electrical and pH monitoring modalities to record extracellular activity. We employ Parylene C, a highly biocompatible material, as a flexible culture substrate that controls the cellular microtopography and promotes a more in vivo-like morphology of neonatal rat ventricular myocytes. Moreover, we transfer the patterning technology on commercially available Multi-Electrode arrays to highlight the potential of integration with products customly used for extracellular electrical recordings. Finally, we implement flexible Parylene sensors for spatiotemporal pH monitoring, using the material both as a support medium and as a sensing membrane. Integration of these three attributes may deliver a compact solution with high scientific and commercial impact.

Parylene C has been extensively used as a biocompatible encapsulation material of implantable microdevices. Towards a new understanding of the material's potential, we demonstrate a versatile method that enables the deployment of the material both as an encapsulant and as a H002B; sensing membrane in a single flexible platform using discrete MOSFETs to evaluate its chemical sensing performance. A 40-electrode array was implemented through standard microfabrication techniques on a free-standing 5 μm Parylene film. A thin film (1 μm) of Parylene was finally deposited on top of the array to passivate the electrode tracks. O2 plasma treatment was employed to selectively functionalize Parylene's H002B; sensing capacity. Measured results indicate a chemical sensitivity of 22.8 mV/pH, while the device exhibits relatively low leakage currents (1.2-13.9 nA) and chemical drifts (10-32 mV/h) over a wide pH range (4-10), rendering Parylene a promising material in the field of flexible bio-sensors.