Deep brain stimulation (DBS) is widely used for neural prosthetics and brain-computer interfacing. Thus far in vivo implantation of a battery has been a prerequisite to supply necessary power.Although flexible energy harvesters have recently emerged as an alternative to the battery, they generate insufficient energy for operating brain stimulation. Herein, we report a high performance flexible piezoelectric energy harvester enabling self-powered DBS in mice. This device adopts an indium modified crystalline Pb(In1/2Nb1/2)O3 -Pb(Mg1/3Nb2/3)O3 -PbTiO3 (PIMNT) thin film on a plastic substrate to transform tiny mechanical motions to electricity. By slight bending, it generates an extremely high current reaching 0.57 mA which satisfies high threshold current for real-time DBS of the motor cortex and thereby could efficiently induce forearm movements in mice. The PIMNT based flexible energy harvester could open a new direction for future in vivo healthcare technology using self-powered biomedical devices.
Broader contextImplantable biomedical devices have attracted a great attention in light of improving the quality of life and prolonging the life expectancy of human. The implantable electronics are widely used in various parts in the patient's body as medical remedy tools such as deep brain stimulation (DBS), cardiac pacemaker, visual prosthesis, and cochlear implant, by electric stimulation of nerve/muscle and monitoring of health condition. However, the conventional implanted batteries have limited lifetime, fixed energy density, and large volume. Recently, many research teams have explored energy harvesting technology which scavenges electricity from biomechanical energy sources to eliminate the implantable batteries or directly stimulate nerve/muscle. Flexible piezoelectric energy harvester is a promising candidate to realize the self-powered implantable bioelectronics, since it can harvest electric energy from inexhaustible slight motions of organs such as heart, lung, and diaphragm. This work has introduced a new platform of self-powered DBS via a high-performance flexible piezoelectric harvester to directly excite neuron of living brain for inducing behavioural changes.A self-powered deep brain stimulation was demonstrated by a flexible piezoelectric PIMNT energy harvester to induce behavioural change of mouse.