Advanced course on ELECTRICAL CHARACTERISATION OF NANOSCALE SAMPLES & BIO-CHEMICAL INTERFACES: methods and electronic instrumentation.

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1 Advanced course on ELECTRICAL CHARACTERISATION OF NANOSCALE SAMPLES & BIO-CHEMICAL INTERFACES: methods and electronic instrumentation. ELECTRONICS for NANO-BIO scientists : an introduction to the course Marco Sampietro Electronics is. the art of controlling the motion of charges in a medium Typically electrons, but also ions in order to retrieve and/or transfer information. 1

2 Electronic measurement is. the art of measuring the motion of charges current, I number of charges charge, Q energy of charges voltage, V in order to retrieve information. OUR WORLD Optical Electrical Bio-Chemical Device under test (DUT) Mechanical I(t) Electronic instrument Physical Magnetic 2

3 Example (1) : Molecular conductors Elettrone Reversible Redox Electric equivalent model I DUT Example (2) : REDOX of molecules External metal wire Elettrone - Elettrone - + Reference conductor Molecule Reduction Neutral molecule Electric equivalent model I DUT 3

4 Example (2) : continue. neutral Liquid environment (Electrochemical interfaces) 500μm 1 st Stage N C P 2 nd Stage N C P Differentiation REDOX Highly selective 20.0p BW = 8kHz rms = 1.4pA BW = 2.5kHz rms = 0.6pA 10.0p 10pA Stem cells Initial stage of specialisation Neurons 0.0 1ms charges Flag : catecholamine Example (3) : DNA through nanopores Nanopore Device Headstage Main Unit Tunneling Electrodes Ag/AgCl V1 Low-Pass Filter (160Hz) Low-Pass Low-Pass Si Tunneling Current DNA Molecule Ionic Current Ag/AgCl Cstray itun V4 iion V2 V3 Amplifier Amplifier Low-Pass Filter (160Hz) LPF Butterworth (75kHz) HPF AC Coupl. DNA (16Hz) LPF Bessel (25kHz) x48 Low-Pass LPF Bessel (2.5kHz) A. Ivanov et al., Nano letters, 2011, 11, sequencing M U X 2 Duplicated Channels T. Albrecht et al., Nature Communications, 2012, 3, 829. D. Branton et al., Nature biotechnology, 2008, 26,

5 Example (4) : counting of cells Cells IN Inlets Impedance Cells OUT 1cm 10µm diameter, 20 bid/s IDS Resistance tracking with time Example (5) : peeping light V AC i AC C A C A light induces a change of R WG light R WG sensed through the oxide in an electronic way 5

6 Questions for scientists How to measure currents? How difficult is to measure small current signals? How to induce a current in the DUT? Why CMOS integration? MICROFLUDIC PDMS CHANNEL SENSING AREA SUBSTRATE CONNECTIONS INSTRUMENT-ON-CHIP LOW-NOISE LOCK-IN FRONT-END ΣΔ ADC 3mm 1 mm Tens of cm 2 Active area 1mm 2 Portable systems: Kg g, 50cm mm, W mw ( mw) Low fabrication cost (CMOS) Simplify the experimental setup: in principle all the relevant functions in few mm 2 Array of sensors. Ex.: CMOS image sensor 6

7 Why CMOS integration? Current noise[a/sqrt(hz)] 1p 100f 10f 1f 100 1k 10k 100k 1M Frequency [Hz] Improvement of - SNR - bandwidth! V bias + C DUT Improvement in performance Note that : 10x10x10 nm 3 material has C=0.1aF 5mm 5 mm CHIP MICROMANIPULATOR 150mm 2 C 150 mm 5mm COPPER PLATE 2 40aF Capacitance [zf] zF A = 6V f 0 = 100kHz = 1s = 4zF rms Time [s] M. Carminati et al. ZeptoFarad capacitance detection with a miniaturized CMOS current front-end for nanoscale sensors ; Sensors and Actuators A, Vol.172, pp (2011) 7

8 Current sensing with AFM Conductive probe I DC +i AC (t) Probing nanoscale Bio-impedance Topography C R AC piezo sample V DC Lock-in amplifier + v AC (t) Capacitance Topography controls AFM controller Dielectric constant = 1.9 topography I DC C R AC I-V Z( f ) L.Fumagalli et al. Quantitative nanoscale dielectric microscopy of single-layer supported biomembranes, Nanoletters Vol.9, n.4, (2009) Course PROGRAM BASIC ELECTRONICS 8

9 Course PROGRAM CURRENTS THROUGH LIQUIDS Course PROGRAM EXPERIMENTS & INSTRUMENTATION IN LIQUIDS 9

10 Course PROGRAM IMPEDANCE MEASUREMENTS Course PROGRAM HOW TO REACH VERY HIGH PERFORMANCE 10

11 Course PROGRAM INTEGRATED INSTRUMENTATION Course PROGRAM 2D ELECTRONICS at CRYOGENIC TEMPERATURE 11

12 Course PROGRAM The VISION from the INDUSTRY PARTICIPANTs INTRODUCE THEMSELVES ANUPA ANNA THOMAS AMBROSI ELIA BARSOTTI JONATHAN BONACCHINI GIORGIO ERNESTO BONFADINI SILVIO CARBONI ROBERTO COSTA ANGELI MARTINA AURORA FERRARI LAURA GEBREYES WONDIMU GIORGIO MICHELE GUGLIELMI EMANUELE LAUDATO MARIO MARRA CRISTIANO ROCCO MASPERO FEDERICO MEMON FAISAL AHMED MUSSI GIORGIO NAVA DIEGO PEDRETTI GIACOMO POLINO NICOLA FRANCESCO RAGNI ANDREA SCURATTI FRANCESCA STUCCHI ELENA VARO SIMONE MI - (1376) FISICA / PHYSICS CENTRO MICROBIO ROBOTICA CMBR-IIT MI - (1376) FISICA / PHYSICS MI - (1376) FISICA / PHYSICS MI - (1379) INGEGNERIA DEI MATERIALI / MATERIALS ENGINEERING CENTRO MICROBIO ROBOTICA CMBR-IIT UNIVERSITA' DEGLI STUDI, MILANO CEA GRENOBLE (Francia) MI - (1376) FISICA / PHYSICS MI - (1376) FISICA / PHYSICS 12

13 PRACTICAL INFO Exam: Test on the WEB (you connect from your site) About 20 questions with multiple answers We have to decide when, before or after Christmas Sign your presence at every lesson! Satisfaction report, every day for every lesson by everybody PRACTICAL INFO (2) Tomorrow (Tuesday) evening, we can have a beer together. Meeting point : here in front of the entrance at (Happy hour). 13