One of the many applications of organ-on-a-chip (OOC) technology is the study of biological processes in human induced pluripotent stem cells (iPSCs) during pharmacological drug screening. It is of paramount importance to construct OOCs equipped with highly compact in situ sensors that can accurately monitor, in real time, the extracellular fluid environment and anticipate any vital physiological changes of the culture. In this paper, we report the co-fabrication of a CMOS smart sensor on the same substrate as our silicon-based OOC for real-time in situ temperature measurement of the cell culture. The proposed CMOS circuit is developed to provide the first monolithically integrated in situ smart temperature-sensing system on a micromachined silicon-based OOC device. Measurement results on wafer reveal a resolution of less than ±0.2 °C and a nonlinearity error of less than 0.05% across a temperature range from 30 to 40 °C. The sensor's time response is more than 10 times faster than the time constant of the convection-cooling mechanism found for a medium containing 0.4 ml of PBS solution. All in all, this work is the first step towards realizing OOCs with seamless integrated CMOS-based sensors capable to measure, in real time, multiple physical quantities found in cell culture experiments. It is expected that the use of commercial foundry CMOS processes may enable OOCs with very large scale of multi-sensing integration and actuation in a closed-loop system manner.@en

The digitization of smart catheters will dramatically increase the demand for reliable and high data transmission in the distal tips. Optical fiber is a good candidate to provide high-speed data transmission. However, the extremely small size of the smart catheter tip, with less than a few millimeters in diameter, hampers the integration of optical fiber connections in the catheter tip. Our work presents a stand-alone optical data link module (ODLM) with a dimension of 240 μm × 280 μm × 420 μm for use in a 1 mm diameter intravascular ultrasound (IVUS) smart catheter. The fabrication of the ODLM is based on the Flex-to-Rigid (F2R) integration technology. In the ODLM, the flexible interconnects reroute the electrical contacts of the flip-chipped vertical-cavity sur-face-emitting laser (VCSEL) to the side of the device. This design enables the ODLM to be mounted on a flex-PCB and fit into a 200-300 μm gap in the IVUS catheter tip. An optical fiber that runs parallel to the catheter shaft is self-aligned to a commercially available VCSEL by inserting it into the through-silicon hole (TSH) of the ODLM. Clear eye diagrams prove the stand-alone ODLM can transmit 25.8 Gb/s, 231-1 Pseudo-Random Binary Sequence (PRBS) when driven through a high-speed bias-tee. The BER test indicates that error-free operation can be achieved at an optical output of around -4 dBm.@en

We present the first Organ-on-Chip equipped with a low-impedance Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) MicroElectrode Array (MEA). The novel device allows simultaneous mechanical stimulation with a stretchable PDMS membrane and electrical monitoring via the PEDOT:PSS MEA of multiple in vitro cell cultures. The surface area enhancement and the morphology of the PEDOT:PSS allows an increase of the charge injection per unit area at the electrode-electrolyte interface, resulting in significantly lower electrochemical impedance of the electrodes. In particular, at 1 kHz the fabricated PEDOT-MEA electrodes show a reduction of the overall impedance up to 99.4 and 93.3 % in comparison with benchmark TiN and Pt electrodes. The superior performance of PEDOT:PSS were also confirmed via Cyclic Voltammetry measurement, in which PEDOT:PSS showed a very large capacitive current, compared with the benchmark electrodes both in the forward and the reverse scans. The obtained results confirm the effectiveness of the proposed PEDOT:PSS coating, and introduce this material in the OOC field. Moreover, the quality and morphology of the fabricated PEDOT:PSS based electrodes were assessed via SEM imaging and Raman spectroscopy.@en