Lidia Maddiona

Fully printed organic CMOS technology on plastic substrates for digital and analog applications

Drastic efforts have been realized these last years in order to develop complementary organic technology. This is the essential key to produce elementary low-cost circuits for digital and analog applications. Different techniques [1–3] are available nowadays to obtain both N- and/or P-type organic devices. Screen printing is one of the most highly awaited low-cost techniques that can be used to produce organic devices and circuits. It has been widely used in P-type organic technologies [4, 5]. Now that N-type semiconductors have become much more easily processed, developers are seeking a complete CMOS and lifetime robust technology. Many previous works have reported on a complete solution based on CMOS technology [6–8]. Large-area-compatible organic processes have also been demonstrated [9]. Nevertheless some of the technological steps in these latter reports are not fully printed and/or still present some lithography/vacuum deposition steps. We present here a complete fully printed CMOS technology on flexible substrates showing acceptable device performances and digital/analog circuit functionalities, which can lead to more complex designs.

High performance printed N and P-type OTFTs for complementary circuits on plastic substrate

This paper presents a printed organic complementary technology on flexible plastic substrate with high performance N and P-type Organic Thin Film Transistors (OTFTs), based on small-molecule organic semiconductors in solution. Challenges related to the integration of both OTFT types in a common complementary flow are addressed, showing the importance of surface treatments. Data on single devices and elementary complementary digital circuits (inverters and ring oscillators) are presented, demonstrating that a robust and reliable flow with high electrical performances can be established for printed organic devices.

Design of analog and digital building blocks in a fully printed complementary organic technology

The paper presents several analog and digital building blocks designed using OTFT devices manufactured in a fully-printed complementary organic technology. Circuit performance and parametric variability are simulated based on a model developed specifically for this technology. Fully-static logic gates and flip-flops as well as a low-area dynamic flip-flop enabled by the use of complementary OTFTs are measured, showing good agreement with simulations. A comparator exploiting offset cancellation techniques achieves a measured offset of less than 200mV. In addition, small-sized envelope detectors are measured at the HF RFID frequency (13.56MHz), to demonstrate the high frequency performance of the OTFTs. All these circuits are building blocks for the realization of a printed RFID tag.

Progresses towards a processing pipeline in photoplethysmogram (PPG) based on SiPMs

We report progresses in the development of a processing pipeline intended for photoplethysmogram (PPG) based on the use of silicon photomultipliers (SiPMs) detectors. Such probe sensors offer relevant advantages in terms of single-photon sensitivity and high internal gain for relatively low reverse bias. Along with the SiPMs detectors, an ad-hoc processing pipeline, we developed, offers advantages e.g. in order to correct signal distortions. The processing pipeline is composed by the PPG raw signal filter, consisting of a FIR pass-band scheme (low-pass filter plus high-pass ones), the PPG pattern recognition system, and completed with the medical indicators detection system and the indicators extraction.