[paper] integrated PD SOI CMOS microcantilever biosensor

Yi Liu, Yuan Tian, Cong Lin, Jiahao Miao & Xiaomei Yu*

A monolithically integrated microcantilever biosensor 

based on partially depleted SOI CMOS technology

Microsystems & Nanoengineering volume 9, Article number: 60 (2023)

DOI: 10.1038/s41378-023-00534-y

* School of Integrated Circuits, Peking University, National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Beijing, 100871, China

Abstract: This paper presents a monolithically integrated aptasensor composed of a piezoresistive microcantilever array and an on-chip signal processing circuit. Twelve microcantilevers, each of them embedded with a piezoresistor, form three sensors in a Wheatstone bridge configuration. The on-chip signal processing circuit consists of a multiplexer, a chopper instrumentation amplifier, a low-pass filter, a sigma-delta analog-to-digital converter, and a serial peripheral interface. Both the microcantilever array and the on-chip signal processing circuit were fabricated on the single-crystalline silicon device layer of a silicon-on-insulator (SOI) wafer with partially depleted (PD) CMOS technology followed by three micromachining processes. The integrated microcantilever sensor makes full use of the high gauge factor of single-crystalline silicon to achieve low parasitic, latch-up, and leakage current in the PD-SOI CMOS. A measured deflection sensitivity of 0.98 × 10−6 nm−1 and an output voltage fluctuation of less than 1 μV were obtained for the integrated microcantilever. A maximum gain of 134.97 and an input offset current of only 0.623 nA were acquired for the on-chip signal processing circuit. By functionalizing the measurement microcantilevers with a biotin-avidin system method, human IgG, abrin, and staphylococcus enterotoxin B (SEB) were detected at a limit of detection (LOD) of 48 pg/mL. Moreover, multichannel detection of the three integrated microcantilever aptasensors was also verified by detecting SEB. All these experimental results indicate that the design and process of monolithically integrated microcantilevers can meet the requirements of high-sensitivity detection of biomolecules.

FIG: a) Micrograph of the fabricated integrated microcantilever sensor IC.
b) SEM photograph of the microcantilever array

Acknowledgements: This research was funded by the National Natural Science Foundation of China (Grant No. 61935001).

Open Access: this article is licensed under a Creative Commons Attribution 4.0 International License 

Multiphysics Simulation of Biosensors

M. Madec, L. Hébrard, J. Kammerer, A. Bonament, E. Rosati and C. Lallement

Multiphysics Simulation of Biosensors Involving 3D Biological Reaction-Diffusion Phenomena in a Standard Circuit EDA Environmen

IEEE Transactions on Circuits and Systems I: Regular Papers.

doi: 10.1109/TCSI.2018.2885223

Abstract: The topic of this paper is the development of biological models for 3D reaction-diffusion phenomena that can be used in any circuit electronic design automation environment for the simulation of biosensors. Biological systems that involve such 3D phenomena are described by partial differential equations. Our approach consists in discretizing these equations according to the finite-difference method and converting the resulting ordinary differential equations into an assembly of elementary electronic equivalent circuits that are directly simulated with SPICE. The main interest of this approach is the ability to couple such models with third-party SPICE models of electronic circuits, sensors, and transducers, i.e., models from any physical domain ruled by Kirchhoff laws, allowing modeling and simulation of any multi-physics systems in a conventional circuit design environment, here CADENCE. The tool is validated on simple problems for which analytical solutions are known. Then, the interest of the approach is illustrated on the study of a biosensor.

URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8602461&isnumber=4358591