Nanobonding: A key technology for emerging applications in health and environmental sciences

Abstract

In this paper, surface-activation-based nanobonding technology and its applications are described. This bonding technology allows for the integration of electronic, photonic, fluidic and mechanical components into small form-factor systems for emerging sensing and imaging applications in health and environmental sciences. Here, we describe four different nanobonding techniques that have been used for the integration of various substrates — silicon, gallium arsenide, glass, and gold. We use these substrates to create electronic (silicon), photonic (silicon and gallium arsenide), microelectromechanical (glass and silicon), and fluidic (silicon and glass) components for biosensing and bioimaging systems being developed. Our nanobonding technologies provide void-free, strong, and nanometer scale bonding at room temperature or at low temperatures (<200 °C), and do not require chemicals, adhesives, or high external pressure. The interfaces of the nanobonded materials in ultra-high vacuum and in air correspond to covalent bonds, and hydrogen or hydroxyl bonds, respectively.

Microfabricated electrochemical pH and free chlorine sensors for water quality monitoring: recent advances and research challenges

“…23,24 There are reports of several hydrogel-based sensors using micro chemical-mechanical transducers for the measurement of pH. Recent developments in microfabrication technologies enable the realization of such sensors.…”

“…Also, micro-scale sensors can be integrated with other components to create high-functionality integrated systems for automatic operation. 23,24 There are reports of several hydrogel-based sensors using micro chemical-mechanical transducers for the measurement Matiar M. R. Howlader of pH. [25][26][27][28] However, these sensors are not widely studied and are more difficult to implement due to their brittle structures and long response time (hundreds of minutes).…”

Integration of Heterogeneous Materials for Wearable Sensors

“…Combined with simple etching or liftoff techniques for patterning layers, it can be used for simple sensor structures incorporating heterogeneous materials. It has been demonstrated for systems involving metals on flexible substrates [ 99 , 100 ] as well as for the integration of different conventional semiconductor materials [ 101 , 102 ]. As Figure 4 shows, in SAB, surfaces of different materials form a strong bond when they are brought into contact after activation by plasma bombardment [ 103 ].…”

Portable Nanohybrid Paper-Based Chemiresistive Sensor for Free Chlorine Detection

“…However, their sensing results are strongly affected by the pH, flow rate, and aging of the electrodes. , Moreover, they have a large size, thereby making them difficult to integrate . To address these limitations, microfabricated electrochemical sensors are being developed as alternative approaches owing to their small size, low cost, ease of integration with other components to form integrated detection systems, and their ability to inhibit electrolyte replenishment . Several researchers have used microfabrication technology to fabricate working electrodes of noble metals such as gold and platinum to develop amperometric free chlorine sensors. − A boron-doped, diamond electrode-based sensor fabricated using microwave plasma-assisted chemical vapor deposition methods increased the device lifetime .…”