Venue: ESPC 2022 Competition

Reviews:

final_score: rating: 2: Borderline. Accept this work only if room. 
review_content: summary: Chemiresistive Sensors for Environmental Monitoring is borderline because it is a resubmission of existing research. The research concept  is strong and the work has already been published. However it is not in the spirit of student competition for Environmental sensing innovation. 

strengths: This is a peer-reviewed mature solution and the solution has been described in IEEE publication: "Ultra-Fast NO2 Detection by MoS2 Nanoflakes at Room Temperature" https://ieeexplore.ieee.org/document/9818849.

Chemiresistive Sensors for Environmental Monitoring team develops MoS2 based sensors to detect NO2 at room temperature. 

The market value for MOS (Metal Oxide semiconductor) sensors is large. There is increasing usage of MOS in HVAC system for gas detection and the  market is forecasted to reach $19.5 billion by 2027,

The solution description is well described and introduces Nanoflakes characterization. The usage of nanostructured metal oxide semiconductor (NMOS) based technologies for sensing greenhouse gas emission is another factor for the growth of the market. 

The prototype is advanced. 
weaknesses: This is a mature solution that has already been with a peer reviewed https://ieeexplore.ieee.org/document/9818849. This infers that no new work was done or achieved for this competition. 

The research has significant value for air quality sensing but industry providing low-cost MOS sensors is quite developed. The research is not easily scalable or easily replicable by industry.
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final_score: rating: 4: Accept + Potential Winner. This work can be presented and it is a strong contender to win this competition.
review_content: summary: This project presents proof-of-concept of developing a portable resistive sensor for detecting some of the air pollutants. From the results, the proposed method has the highest response to NO2. 
strengths: 1. The project is well designed with clear target, good presentation of the paper and video.
2. The project provides an end to end solution for air pollutant sensing.
3. The project aims to design portable sensors, which is an important for real-time sensing and potential applications based one measurements of portable devices.
4. The project also points out the weakness and future direction.

weaknesses: 1. As mention in the abstract, the project is a kind of proof-of-concept. The experiment is also carried out in the well-designed environment. It would be interesting to see the performance of the portable sensor in real environment.
2. A pointed out the authors, weakness of the current design, such as the lifespan of the sensor, which could only be used for 21days. Does the added fluid shorten the lifespan of the sensor?
3. Table 1 does not give much related information for the proposed project.
4. The left picture in Figure 4 is clear, while what is the right picture in Figure 4 means, the words (eg., methanol and acetone) are not mentioned in the project.
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final_score: rating: 4: Accept + Potential Winner. This work can be presented and it is a strong contender to win this competition.
review_content: summary: In this work, low-power, and low-cost MoS2-based sensors have been developed to detect NO2 at room temperature. An end-to-end system is developed along with PCB, microcontroller and a display. The work looks interesting, important and the report is well written. 
strengths: 1. The report is well-written, and the video presentation is good.
2. Results look interesting
3. Future work looks good.
weaknesses: 1. Given the work is on NO2, not sure why the whole of table 1 is required.
2. No comparison with existing techniques in terms of cost or performance is done. What is the cost of this sensor?
3. Is 41% response good for the gases? What is the accepted range.
4. It is not clear how humidity and temperature values are used.
5. What are the false detections if the sensor is used as NO2 sensor but there are high NH3 or acetone values?
6. ESP32 would have been better as compared to ATMEGA that way, data could have been stored on the cloud. Not sure how data was collected and how much data was collected at what frequency.
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final_score: rating: 4: Accept + Potential Winner. This work can be presented and it is a strong contender to win this competition.
review_content: summary: The authors present their chemresistive sensor. Specifically, a portable resistive sensor for detecting NO2.
strengths: - The problem is very important for air quality sensing, and the solution provided is timely and relevant. 
- The authors build an end-to-end sensing solution, which also involves building a sensor and creating a circuit to read the values from the sensor. Furthermore, they have integrated a built in display with their sensor which improves the deployability and usability. 
- The video is very detailed and the authors do a very good job in summarizing the entire process along with the details of the design. 
- The authors also present the strengths, weaknesses, and avenues to improve their work. 


weaknesses: - It is not clear why you are also displaying the humidity and temperature. Why is this important, and what would be the impact of just looking at the NOx values without looking at the temperature and humidity. 
- What was the reason for selecting 45% Ethanol and 55% Water when making the solution. If this has been discussed in article [10], then please summarize the key findings of your past work [10]. Note that the template provided would have given sufficient space for you to add more text. 
- It is not clear why your sensor shows 80ppm when you have a flow 100 ppm?

Some nitpicks
- One cannot claim that air pollution is the primary reason for climate change. It is a key factor but to make the claim that it is the primary reason would require some supporting citations. 
- Do a spell check on the document. Examples for mistakes include 'poluution', 'socities'.
- The units for the values in Table 1 were not specified. But it was nice that you clarified it in the video. 
- For those not conversant with the periodic table it would be nice to remind us what is Mo (Molybdenum). 
- What is the cost of making your sensor? Have you looked at the quantifying the total cost including the energy costs?
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Decision: Accept