Changes in humidity, temperature, and pressure influence the physical properties of many materials. We built an instrument which characterizes how a material behaves under different environmental conditions. This enables researchers to study the suitability of certain materials for use as environmental sensors and to investigate the longevity of materials which are exposed to extreme environmental conditions.
Advances in materials synthesis and nanoscale patterning techniques have led to rapid development of a wide variety of novel functional materials. Before they can be deployed in technological applications, these materials must be screened for functionality and stability under a broad range of environmental conditions to test for performance and long-term stability. To facilitate high-throughput material screening, we developed a controlled environmental chamber for in situ monitoring of thin film behavior under controlled environments. The foundation of the system is a vacuum chamber in which precise levels of humidity, pressure, temperature, light intensity, gas/vapor flow rates and mixtures can be controlled by custom software. A broad range of instruments integrated with the control software enable multi-channel in situ measurement of electrical, optical, and gravimetric/viscoelastic properties of thin films inside the chamber. The central software which controls the system is written in LabVIEW and Python, allowing for full customizability to accommodate specific sample constraints and flexible user-designed measurement sequences. The system has been used to characterize dynamic environmental response of a wide range of thin film materials including metal oxides, carbon nanotubes, 2D materials (graphene, MXenes, etc.), polymers, ionic liquids and perovskites (see references below).
- Assessment of long-term optoelectronic device performance and degradation under controlled environment
- Assessment of performance of environmental sensors
- Assessment viscoelastic properties of thin films under changing environment
- Assessment of UV irradiation on film behavior
- Measurement of adsorption isotherms under different gas/vapor compositions
- Correlation of optoelectronic properties with gravimetric/viscoelastic properties as films adsorb/desorb gas/vapor
- Environmental control
- Pressure: 1 mTorr – 760 Torr
- Relative humidity: 0.1% – 100%
- Temperature: 25°C – 100°C
- Gas/vapor mixtures: H2O, O2, N2, CO2, Ar at 5 – 400 sccm flow rate
- UV and IR lamps with 4” diameter window in situ UV irradiation and heating
- Electrical (up to 4 channels)
- Zahner IM6 electrochemical workstation: impedance spectroscopy from 1 mHz – 8 MHz in galvanostatic or potentiostatic modes, 0-4 VDC bias and 1 mV – 3 VAC excitation, ms-resolution pulsed photoresponse, high impedance probes for impedance measurement up to 100 TΩ
- Keithley 2420: pA current measurement, 1 uV to 60V output bias
- Keithley 4200 semiconductor characterization system: pA current resolution, ms time resolution for electrical device characterization using 2-probe and 4-probe IV, CV, and transistor measurements
- Multiplex board for option of up to 48 simultaneous electrical connections
- Gravimetric (up to 6 channels)
- Quartz crystal microbalance with dissipation monitoring, 5 MHz and 10 MHz resonant frequency crystals, up to 25th crystal harmonic for multi-frequency gravimetric and viscoelastic response
- Multi-harmonic KSV-Z500 QCM-D system, SRS QCM200, Arduino-integrated openQCM, SARK-110 impedance analyzer for measurement of full QCM conductance spectra
- Optical feedthroughs with OceanOptics UV/VIS spectrometers for measuring optical transmittance under controlled environment
- Muckley, E.S., Collins, L.F., Ievlev, A.V., Ye, X., Kisslinger, K., Sumpter, B.G., Lavrik, N.V., Nam, C.Y. and Ivanov, I.N., 2018. Light-activated hybrid nanocomposite film for water and oxygen sensing. ACS applied materials & interfaces. 10(37), pp.31745-31754.
- Tatarko, M., Muckley, E.S., Subjakova, V., Goswami, M., Sumpter, B.G., Hianik, T. and Ivanov, I.N., 2018. Machine learning enabled acoustic detection of sub-nanomolar concentration of trypsin and plasmin in solution. Sensors and Actuators B: Chemical, 272, pp.282-288.
- Muckley, E.S., Naguib, M., Wang, H.W., Vlcek, L., Osti, N.C., Sacci, R.L., Sang, X., Unocic, R.R., Xie, Y., Tyagi, M., Mamontov, E., Page, K.L., Kent, P.R.C., Nanda, J., and Ivanov, I.N., 2017. Multimodality of Structural, Electrical, and Gravimetric Responses of Intercalated MXenes to Water. ACS nano, 11(11), pp 11118–11126.
- Muckley, E.S., Jacobs, C.B., Vidal, K., Lavrik, N.V., Sumpter, B.G., and Ivanov, I.N., 2017. Multi-mode humidity sensing with water-soluble copper phthalocyanine for increased sensitivity and dynamic range. Scientific Reports, 7(1) 9921.
- Muckley, E.S., Jacobs, C.B., Vidal, K., Mahalik, J.P., Kumar, R., Sumpter, B.G. and Ivanov, I.N., 2017. New Insights on Electro-Optical Response of Poly (3, 4-ethylenedioxythiophene): Poly (styrenesulfonate) Film to Humidity. ACS Applied Materials and Interfaces, 9(18), pp.15880-15886.
- Jacobs, C.B., Maksov, A.B., Muckley, E.S., Collins, L., Mahjouri-Samani, M., Ievlev, A., Rouleau, C.M., Moon, J.W., Graham, D.E., Sumpter, B.G. and Ivanov, I.N., 2017. UV-activated ZnO films on a flexible substrate for room temperature O2 and H2O sensing. Scientific Reports, 7(1) 6053.
- Muckley, E.S., Lynch, J., Kumar, R., Sumpter, B. and Ivanov, I.N., 2016. PEDOT: PSS/QCM-based multimodal humidity and pressure sensor. Sensors and Actuators B: Chemical, 236, pp.91-98.