Combining the Maker Movement with Accessibility Needs in an

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Combining the Maker Movement with Accessibility Needs in an Undergraduate Laboratory: A Cost-Effective Text-to-Speech Multipurpose, Universal Chemistry Sensor Hub (MUCSH) for Students with Disabilities Ronald Soong,* Kyle Agmata, Tina Doyle, Amy Jenne, Tony Adamo, and Andre Simpson University of Toronto, Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada

J. Chem. Educ. Downloaded from pubs.acs.org by 95.181.177.96 on 10/25/18. For personal use only.

S Supporting Information *

ABSTRACT: With the advances in open-source technology, many laboratory devices can be built with a modest budget, particularly assistive laboratory devices. The current market cost of most assistive laboratory devices is a major barrier for students with accessibility needs. Specifically, for students with visual impairment, their limited choice of laboratory assistive devices has motivated us to construct a low-cost, multipurpose sensor hub capable of connecting to a pH electrode or a thermocouple, two sensors commonly used in many chemistry teaching laboratories. In this technology report, we present the construction of a text-to-speech (TTS) multipurpose universal chemistry sensor hub (MUCSH) built using an Arduino platform and other associated open-source electronic parts. The cost of this device is between $200 and $300, a fraction of the cost of commercially available products, which cost thousands of dollars. KEYWORDS: First-Year Undergraduate/General, Laboratory Equipment/Apparatus, Analytical Chemistry, Collaborative/Cooperative Learning, Laboratory Computing/Interfacing

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equipment, such as pH electrodes and thermocouples.4 In our attempt to address this issue, we have developed and constructed an open-source, multipurpose text-to-speech (TTS) sensor hub for chemistry teaching laboratories, namely, the multipurpose, universal chemistry sensor hub (MUCSH). This hub can connect to a pH electrode as well as to a thermocouple, two commonly used sensors in chemistry experiments. The construction of this device is based on an Arduino microcontroller coupled with an Arduino-compatible TTS module (Emic 2 Text-to-Speech) from Parallax Inc.5 Arduinos are versatile, open-source microcontrollers that have become highly popular in chemical education and various Maker communities.6−15 For instance, a range of devices can be created for chemical education, from a simple photometer to a potentiostat for electrochemical applications.6−15 TTS is a common feature in most computing devices, including smart phones and tablets. However, accessing these features such that values from a sensor can be read out loud is challenging because of various technical-compatibility issues. Therefore, we decided to construct this device using an Arduino platform, mitigating any hardware- or software-compatibility problems. Also, the Arduino platform is highly affordable, allowing us to

INTRODUCTION Overcoming the learning barrier for students with disabilities in teaching laboratories has been a major endeavor.1,2 Although significant efforts have been made in improving access to laboratories for many students, much of the equipment remains inaccessible to students with disabilities.1−3 Because most laboratory assistive technologies can be expensive, typically thousands of dollars, students with visual impairment are often left out of many laboratory activities.3 In addition, students with disabilities are frequently discouraged from pursuing careers in the sciences because of various social and economic barriers.1−3 These students often face stereotypes and ignorance regarding their potential in science, technology, engineering, and mathematics (STEM) education and related careers.1,2 On the basis of recent studies, only 2.4% of scientists and engineers in the workforce with disabilities are younger than 35 years of age.1,2 Therefore, there is an urgent need to better assist students with disabilities, allowing them to achieve their full potential in STEM. Accessibility in the laboratory can be easily achieved through the principle of universal design.3 Interestingly, for most teaching laboratories, the issue with accessibility lies in the laboratory equipment used to conduct the experiments.3 Much laboratory equipment is designed for able-bodied users, with accuracy and precision in mind.3 Understanding that not all laboratory equipment can be made accessible, we have chosen to create a laboratory assistive device based on commonly used © XXXX American Chemical Society and Division of Chemical Education, Inc.

Received: August 7, 2018 Revised: September 29, 2018

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DOI: 10.1021/acs.jchemed.8b00638 J. Chem. Educ. XXXX, XXX, XXX−XXX

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the pH sensor or temperature sensor is in the solution, the device is able to convert the readings from the sensor to audio outputs. The sound quality was exceptional considering the cost of this device. The sensitivity and dynamic range of these sensors are adequate for undergraduate experiments. We have performed several calorimetry experiments using an immersible thermocouple, as shown in Figure 2. A standard experiment was performed via investigating the heat of neutralization of hydrochloric acid (HCl) and sodium hydroxide (NaOH). Through the automatic recording of data points, a sufficient amount of data was collected at the most critical junction, allowing the students to properly characterize a cooling curve and reaction processes. Because there is a time delay for each audio output, that could significantly affect the temporal resolution of the data set. Therefore, the program is written such that only the highest and lowest temperature values are read out after a complete cooling curve is acquired, which enables the calculation of the enthalpy of neutralization. On the basis of the cooling curve, we calculated the heat of neutralization to be 58 kJ/mol, which is consistent with literature values. Titration of acids and bases is one of the most commonly performed experiments in a chemistry teaching laboratory. We have adapted our device to work with a pH electrode, as shown in Figure 3, such that it can read out pH values for students with visual impairment as they perform titration using a micropipette. For laboratory safety, it is possible to plug a Bluetooth transmitter dongle into the headphone jack so that a wireless headphone can be used without additional programming, avoiding the unnecessary loose wire on the lab bench. The pH electrode can be easily calibrated according to instructions from the manufacturer.19 In this case, the micropipette was calibrated to 200 μL per injection. The following titration curve was obtained via a manual-titration method with audible output of pH values. The titration curve is shown in Figure 4. On the basis of this setup, not only are students with visual impairments able to use the pH electrode to learn about the fundamentals of acids and bases, but they can also perform simple acid−base titration using a micropipette. In addition to acid−base titration, this device, with a few modifications, can also be used for other titration-based experiments, such as potentiometric titration, allowing for a greater range of experiments to be performed at the undergraduate level. Understanding that this device only addresses the titration aspects of the experiments, assistance for other part of the experiments, including volume measurement and dilution, is required for students with visual impairments. This is certainly a first step in achieving full laboratory participation, empowering students with disabilities in the process. Although this device can only address needs based on visual impairments, it is expected that the popularity of open-source technology will start a new wave of do-it-yourself (DIY) devices that address different needs in the laboratory. The total cost of this device ranges from $200 to $300, depending on the source of the parts. On the basis of our testing, this device can bridge the accessibility gap in the laboratory for students with disabilities because of its affordability and flexibility. Compared with a commercially available assistive device (http://independencescience.com/ product/talking-labquest-2/) for laboratory teaching, which is in the range of $2000, this device delivers similar options, such as data logging, text-to-speech functionality, and Bluetooth

address the cost barrier of assistive devices in the laboratory.6−15

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MATERIALS AND METHODS The following hardware was purchased from RobotShop Inc. (www.robotshop.com): (1) Arduino UNO, (2) Arduino Prototyping Shield, (3) Emic 2 Text-to-Speech module from Parallax Inc., (4) Jumper Cable, (5) Gravity Analog pH Meter Kit, (6) Gravity Temperature Sensor, (7) DS18B20 Waterproof Digital Temperature Sensor, (8) USB Printer Transfer Cable, and (9) MacBook Air 2012. Sample codes and the connection diagrams (see Figures S1 and S2) can be found in the Supporting Information. All chemicals used were purchased from Sigma-Aldrich unless specified otherwise. The 3D printing was done at the University of Toronto Scarborough (UTSC) Library MakerSpace. The 3D printer used was a MakerBot Replicator 2 that used a polylactic acid (PLA) filament as the substrate for printing. The assembly and schematic of this device are illustrated in Figure 1.

Figure 1. Open-source, universal chemistry sensor hub created by connecting the different Arduino shields together. The TTS module is connected to the breadboard on the Arduino prototyping shield via a male-to-male jumper cable to the appropriate pin on the Arduino as defined by the control code.

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DISCUSSION The assembly of MUCSH was simple and straightforward. The modular-design of this device allows for flexibility, as parts can be adapted on the basis of student needs. For instance, an SDcard reader can be added to the device, allowing for the storage of experimental data and making the device portable when needed. Because of its small size, it can be easily incorporated into any equipment setup on even the smallest lab benches. A simple, small wooden box or 3D-printed enclosure is sufficient to protect this device from damages due to chemical spillage and is an economical and environmentally friendly option for departments on a tight budget. The programming of the device was straightforward. The TTS module comes with a starter code, allowing the user to experiment with the code while learning its many functions.5,16 On the basis of our experience, only a few iterations are required to have the program working for the device.5 (Sample code is given in the Supporting Information.) The operation of the device is also simple. The sensors can be connected to the Arduino with manuals from the manufacturer.17,18 Once either B

DOI: 10.1021/acs.jchemed.8b00638 J. Chem. Educ. XXXX, XXX, XXX−XXX

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Figure 2. (A) 3D-printed calorimeter equipped with an Arduino digital thermometer that allows for automatic logging of temperatures as a function of time. (B) Typical cooling curve acquired using the 3D digital calorimeter described here. In this case, the heat of neutralization between 4 M HCl and 2 M NaOH was investigated.

wireless audio capability, while being able to accommodate accessibility needs based on varying degrees of visual impairment. Because of the popularity of open-source technology, popular vendors, such as Vernier Technology, are beginning to offer some of their sensor technology with Arduino compatibility, allowing for a better selection of sensors for chemistry experiments. The only caveat is that this device requires the user to be comfortable with open-source electronics and programming. With the shift in the paradigm of STEM education in which coding literacy is becoming a major theme, this device and its construction provides an excellent experiential-learning opportunity for students to explore the concepts behind the design and code.

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CONCLUSION In this technology report, we present a multipurpose, universal chemistry sensor hub (MUCSH) to bridge the accessibility gap for individuals with vision impairments in the teaching laboratory. MUSCH is based on a modular-design approach and an open-source Arduino platform. This device can address the accessibility needs for students with visual impairments, as values from sensors are recorded and converted to speech for audio output. The cost of this device is a fraction of that of a commercially available assistive device, and it offers comparable features. Although coding and a basic understanding of electronics are required in the construction of MUCSH, because of the shift in the STEM paradigm where there is a great emphasis on coding literacy, this product will make an excellent teaching tool to introduce students to designing and computer programming.

Figure 3. (A) MUCSH device adapted for use with a pH electrode. (B) Electrode connected to the device for pH titration. C

DOI: 10.1021/acs.jchemed.8b00638 J. Chem. Educ. XXXX, XXX, XXX−XXX

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Figure 4. pH-titration curve produced using MUCSH adapted with a pH electrode. The titrant was carefully dispensed into the solution using a 200 μL micropipette. In this case, 15 mL of 0.1 M HCl was titrated against 0.1 M NaOH. The end point of the titration was approximately 15 mL, which is consistent with our calculation. The pH value was recorded only when the pH readings were stabilized. The pH electrode was calibrated using a script provided by the manufacturer. Two buffer solutions at pH 4 and 10 were used for the calibration.

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(4) Vitoriano, F. A.; Teles, V. L.G.; Rizzatti, I. M.; de Lima, R. C. P. Promoting Inclusive Chemistry Teaching by Developing an Accessible Thermometer for Students with Visual Disability. J. Chem. Educ. 2016, 93 (12), 2046−2051. (5) Emic 2 Text-to-Speech Module Manual. Parallax Inc. https:// www.parallax.com/product/30016 (accessed June 2018). (6) Mercer, C.; Leech, D. Cost-Effective Wireless Microcontroller For Internet Connectivity of Open Source Chemical Devices. J. Chem. Educ. 2018, 95 (7), 1221. (7) Kubínová, Š .; Š légr, J. ChemDuino: Adapting Arduino for LowCost Chemical Measurements in Lecture and Laboratory. J. Chem. Educ. 2015, 92 (10), 1751−1753. (8) Arrizabalaga, J. H.; Simmons, A. D.; Nollert, M. U. Fabrication of an Economical Arduino-Based Uniaxial Tensile Tester. J. Chem. Educ. 2017, 94 (4), 530−533. (9) Jin, H.; Qin, Y.; Pan, S.; Alam, A. U.; Dong, S.; Ghosh, R.; Deen, M. J. Open-Source Low-Cost Wireless Potentiometric Instrument for pH Determination Experiments. J. Chem. Educ. 2018, 95 (2), 326− 330. (10) Grinias, J. P.; Whitfield, J. T.; Guetschow, E. D.; Kennedy, R. T. An Inexpensive, Open-Source USB Arduino Data Acquisition Device for Chemical Instrumentation. J. Chem. Educ. 2016, 93 (7), 1316− 1319. (11) Mercer, C.; Leech, D. Inexpensive Miniature Programmable Magnetic Stirrer from Reconfigured Computer Parts. J. Chem. Educ. 2017, 94 (6), 816−818. (12) Zhang, Q.; Brode, L.; Cao, T.; Thompson, J. E. Learning Laboratory Chemistry Through Electronic Sensors, a Microprocessor, and Student Enabling Software: A Preliminary Demonstration. J. Chem. Educ. 2017, 94 (10), 1562−1566. (13) Mabbott, G. A. Teaching Electronics and Laboratory Automation Using Microcontroller Board. J. Chem. Educ. 2014, 91 (9), 1458−1463. (14) Enciso, P.; Luzuriaga, L.; Botasini, S. Using an Open-Source Microcontroller and a Dye-Sensitized Solar Cell to Guide Students from Basic Principle to a Practical Application. J. Chem. Educ. 2018, 95 (7), 1173. (15) Meloni, G. N. Building a Microcontroller Based Potentiostat: A Inexpensive and Versatile Platform for Teaching Electrochemistry and Instrumentation. J. Chem. Educ. 2016, 93 (7), 1320−1322.

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information contains the following: The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.8b00638.

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Source code for the text-to-speech pH electrode and text-to-speech thermometer, diagram showing how to connect the pH electrode to the sensor hub, and diagram showing how to connect the thermosensor to the sensor hub. (PDF, DOCX)

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Ronald Soong: 0000-0002-8223-9028 Andre Simpson: 0000-0002-8247-5450 Notes

The authors declare no competing financial interest.

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ACKNOWLEDGMENTS We acknowledge the University of Toronto, Scarborough (UTSC), and the UTSC MakerSpace for their generous support of this project. In addition, we acknowledge seedfunding support from the Instructional Technology Innovation Fund from the University of Toronto.

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REFERENCES

(1) Brown, E. Disability Awareness: The fight for accessibility. Nature 2016, 532, 137−139. (2) Shanahan, J. Disability is not a disqualification. Science 2016, 351 (6271), 418. (3) Sukhai, M. A.; Mohler, C. E. Creating a Culture of Accessibility in the Sciences; Academic Press: New York, 2016. D

DOI: 10.1021/acs.jchemed.8b00638 J. Chem. Educ. XXXX, XXX, XXX−XXX

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(16) Language Reference. Arduino. https://www.arduino.cc/ reference/en/ (accessed June 2018). (17) Waterproof DS18B20 Digital Temperature Sensor (SKU: DFR0198), 2017. DFRobot. https://www.dfrobot.com/wiki/index. php/Waterproof_DS18B20_Digital_Temperature_Sensor_ (SKU:DFR0198) (accessed June 2018). (18) PH meter(SKU: SEN0161), 2018. DFRobot. https://www. dfrobot.com/wiki/index.php/PH_meter(SKU:_SEN0161) (accessed June 2018). (19) Yu, Y. DFRobot pH Sensor Calibration, 2016. Codebender. https://codebender.cc/ sketch:397462#DFRobot%20pH%20Sensor%20Calibration.ino (accessed June 2018).

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DOI: 10.1021/acs.jchemed.8b00638 J. Chem. Educ. XXXX, XXX, XXX−XXX