Advances in Physicochemically Stimuli-Responsive Materials for On-Demand Transient Electronic Systems

Advanced Materials in Wireless, Implantable Electrical Stimulators that Offer Rapid Rates of Bioresorption for Peripheral Axon Regeneration

“…Recent advances in stimuli‐responsive materials, such as optically/thermally responsive polymers, suggest potential for devices that degrade rapidly after a user‐defined triggering event. [ 25 ] The integration of sensor functionality presents another set of opportunities, allowing for closed loop control of both operating parameters and device lifetime.…”

Bioresorbable Metals for Biomedical Applications: From Mechanical Components to Electronic Devices

“…The overall hydrolysis reactions for Mg, Zn, and Fe are Mg + 2H 2 O → Mg(OH) 2 + H 2 , Zn + 2H 2 O → Zn(OH) 2 + H 2 , and 4Fe + 3O 2 + 10H 2 O → 4Fe(OH) 4 − + 4H + , respectively. [ 10,43–45 ] Mo and W also resorb through hydrolysis reactions (2Mo + 2H 2 O + 3O 2 → 2H 2 MoO 4 , 2W + 2H 2 O + 3O 2 → 2H 2 WO 4 ), [ 10,46,47 ] although with rates that can be much lower than those of Mg, Zn, and Fe. [ 44 ]…”

“…[ 65 ] Thin‐film dielectrics can be formed with materials such as SiO 2 , MgO, and Si 3 N 4 , with corresponding reactions of SiO 2 + H 2 O → Si(OH) 4 , MgO + H 2 O → Mg(OH) 2 , and Si 3 N 4 + 6H 2 O → 3SiO 2 + 4NH 3. [ 10,113 ] Thin metal conductors (Mg, Mo, Zn, Fe, and W) paired with these materials can yield nearly all of the essential components of advanced electronic systems based on high‐performance complementary metal‐oxide‐semiconductor (CMOS) circuits that incorporate n‐/p‐channel metal‐oxide field‐effect transistors (MOSFETs). Many of the bioresorbable metals originally developed for structural applications, as described in previous sections, but others as well, can be used in this context, as thin coatings formed by modern methods in physical and chemical vapor deposition.…”

“…[ 6–9 ] Mechanisms of bioresorption naturally eliminate a potential source of infectionand of other complications, as well as risks and costs associated with secondary surgical procedures for retrieval. [ 10–13 ] Among various classes of bioresorbable materials, metals are particularly important, historically due to their favorable mechanical properties in structural components. [ 14 ] Since early reports of joint arthroplasties based on magnesium (Mg) plates and sheets in 1900, [ 15–17 ] bioresorbable metals have appeared in many different orthopedic applications, from bone fracture fixture screws, to nails, plates and pins from 1909 to 1948 [ 18–21 ] ( Figure ).…”

Ultrasound-mediated triboelectric nanogenerator for powering on-demand transient electronics

“…Because the long time scale from the loss of energy generation to the complete transience, undesirable burdens, and potential hazards can be induced to the patients. Active operation, the system of which function is terminated with the precisely manipulated stimuli that entails mechanical and/or chemical degradation, has been introduced as a promising approach toward the elimination of negative health consequences (15). Many efforts to take benefits of active operation for transient TENGs have been made using light sources and photo thermal processes, but they are neither available deep in the body nor secured biological safety (16)(17)(18).…”