Issue link: https://iconnect007.uberflip.com/i/1047182
64 SMT007 MAGAZINE I NOVEMBER 2018 millions of wireless sensors and devices like- ly to be transmitting soon, new network pro- tocols are being prepared to facilitate the IoT. The Evolution of Printed Electronics Several decades ago, printed electronics began to become selectively competitive with semiconductor components. Designers com- pared technologies and considered potential applications. While there were some early suc- cesses, purely ink-based solutions couldn't match the cost or performance of silicon-based electronics in all cases. Moore's Law also man- dated that devices based solely on printed inks couldn't match the exponential advance of faster, cheaper transistors. Today, designers mix conventional semicon- ductors with printed electronics to achieve the best of both worlds. Semiconductors are pow- erful and can make products lightweight, flex- ible, and compact when integrated with print- ed electronics. In some cases, they also allow devices to be tether free. Instead of connecting a PCB and radio to a device's architecture, sys- tem architects can achieve integration within the device form factor itself. In addition to sup- porting data collection then, printed electron- ics provide design flexibility. For example, Nypro recently developed a fully-functional proof-of-concept wireless inhaler that repli- cates how a smart inhaler for asthma and COPD patients is expected to work (Figure 4). The future evolution of the device needs to minimize size, sup- port the lowest land- ed cost, and over- come power and space issues that could limit performance. Challenges include finding a way to position a sensor as close to the inhaler's air chan- nel as possible and figur- ing out how to minimize the profile of the sys- tem. Engineers could explore the role of print- ed sensors, batteries, and antennas in helping meet these evolution challenges, and technol- ogy providers could help meet them. In another connected healthcare initiative, Nypro collaborated with 3M to develop a low- power, disposable electrocardiography (ECG) patch that can be worn for seven days. The device measures real-time single-lead ECG and fall episodes using a tri-axis accelerometer. This low-power disposable Bluetooth-enabled patch was integrated on a single flexible hybrid PCB with an average current consumption of 3.6 mA from a 3.0 V stack of four flexible bat- teries. Silver-silver chloride (Ag-AgCl) ink sen- sors were directly printed on the PCB, elimi- nating the need to attach external sensors and making the device smaller, thinner, and more compliant than earlier designs. These devices play an important role in the connected eco- system, and the data collected from them can allow for customization and personalization of healthcare and deliver immense value. Printed electronics also offer benefits from a manufacturing perspective where high-vol- ume processing and a lower total cost of own- ership are especially important. Tradition- al electronics manufacturing is a subtractive process requiring several steps to create one layer. These steps are repeated over and over to get multiple lay- ers. Printed electronics use a two-step additive pro- cess where a substrate is exposed to deposition and then dried and cured. This two-step process can be repeat- ed to develop multilay- er designs. Printed electronics can also reduce or elimi- nate assembly steps where electronics are integrat- ed into final products. With machines and equipment, structur- al electronics (SE) can replace traditional com- Figure 4: Nypro engineers are exploring how print- ed sensors, batteries, and antennas can enable and enhance medical device concepts, such as smart inhalers for asthma and COPD patients.