Environmental Sensors for Air and Water Pollution Monitoring Nan Wang, Jin Wu, M Baranski, S Muttikulangara, L Norford, M Triantafyllou, G Barbastathis and JM Miao June 29, 20151SMART CENSAM

Content  Shark-Inspired MEMS Chemical Sensor for Heavy Metal Detection  3D Graphene Hydrogel based Air Pollutant Sensing  Light Field Imaging Spectrometer for Air Atmosphere Pollutant Monitoring by Satellite 2

Content  Shark-Inspired MEMS Chemical Sensor for Heavy Metal Detection  3D Graphene Hydrogel based Air Pollutant Sensing  Light Field Imaging Spectrometer for Air Atmosphere Pollutant Monitoring by Satellite 3

Heavy metal contamination is considered to be one of the most dangerous pollutants of water pollution, due to its non-biodegradable nature. The contamination can come from many sources, including urban, industrial, mining and agricultural sources. Sources of heavy metal contamination *Figure downloaded from Internet. Background 4

Disadvantages of conventional monitoring method:  time-consuming, labor-intensive sample collection.  unpredictable reactions during transportation.  experimental facilities restricted to centralized place.  requirement of well-trained personnel. Sample Collection Sample Transportation Laboratory Analysis Result Generation Conventional Water Quality Monitoring 5

In nature, some marine animals possess remarkably keen olfactory sensing system, among which shark has well reputed smelling capacity as its olfactory organs are highly responsible for perceiving and analyzing odorant information to initiate food searching. Image of lemon shark Ventral view of the head of lemon shark *Figure downloaded from Internet. Zeiske et al. Inspiration Olfactory organ where in, incurrent nostril; or, olfactory rosette; nf, nasal flap; en, excurrent nostril. 6

Cross-sectional SEM image of olfactory rosette of lemon shark where ic, inlet chamber; r, raphe; ol, olfactory lamella; im, inner lamellar margin; sf, secondary fold; cw, cavity wall; pc, peripheral canal. Inside the olfactory cavity, a large number of olfactory lamellae aggregate a rosette layout to form internal gap system between opposite-facing lamellae for water circulation. Such structure will significantly increase the chances of odorant molecules to be captured by olfactory sensing system. Zeiske et al. Inspiration 7

Reference Electrode (RE) Working Electrode (WE) Counter Electrode (CE) Contact Pad Microfluidic Channel Assembly Mark Inlet Outlet Reaction Chamber Schematic drawing of proposed MEMS chemical sensor with top part (microfluidic channel) and bottom part (sensor base). Concept 8

A (A) Schematic drawing and (B) photograph of our fabricated MEMS chemical sensor. (C) SEM image of shark’s olfactory sensors and (D) SEM image of micropillar electrode array, which mimics the morphological arrangement of shark’s olfactory sensors. Zeiske et al. CD Concept B 9

AB (A)Square wave stripping voltammograms for increasing concentration of Pb under optimized conditions (B)Its calibration curve. Lead (Pb) detection with square wave anodic stripping voltammetry 10

AB (A)Square wave stripping voltammograms for increasing concentration of Cu under optimized conditions (B)Its calibration curve. Copper (Cu) detection with square wave anodic stripping voltammetry 11

Content  Shark-Inspired MEMS Chemical Sensor for Heavy Metal Detection  3D Graphene Hydrogel based Air Pollutant Sensing  Light Field Imaging Spectrometer for Air Atmosphere Pollutant Monitoring by Satellite 12

Graphene under ambient conditions has been observed to display p-type behavior due to the electron withdrawing nature of adsorbed water or oxygen containing moisture, inducing a hole-like carrier concentration. 3D graphene hydrogels have larger surface areas than 2D counterparts. It is favorable for gas absorption and therefore gives higher sensitivity and detection limit for gas. 13 Background 3D graphene hydrogels 2D graphene sheet

Drop cast of 3D graphene hydrogel on electrodes Use wire bonding for electrode Gas sensing test electrode 14 Compare the sensing properties of 3D graphene hydrogel and 2D graphene sheet, Hypothesis: 3D graphene can improve the performance 3D graphene hydrogels were synthesized by one step hydrothermal method. (ACS Nano, 2010, 4, 4324 ) 3D Graphene Hydrogel based Gas Sensor

SEM images of synthesized 3D graphene hydrogel 15 Resistance increases when gas concentration increases Detection of NO2 by 3D Porous Graphene Hydrogel

Contents  Shark-Inspired MEMS Chemical Sensor for Heavy Metal Detection  3D Graphene Hydrogel based Air Pollutants Sensing  Light Field Imaging Spectrometer for Air Atmosphere Pollutant Monitoring by Satellite 16

Background 17 Spectral Imaging –I(x,y, λ) –Spectral fingerprints of atmosphere pollutants (NO,NO 2,SO…) NTU nano-satellites projects –Miniature instrumentation

Concept 18

Thank you ! June 29, 2015SMART CENSAM19