fig5

Figure 5. Tear-based wearable electrochemical sensors for diabetes mellitus. (A) Scheme of needle-type tear glucose sensor. Reproduced with permission^[220]. Copyright 2011, American Chemical Society; (B) Design of flexible glucose sensor attachable to contact lens. Reproduced with permission^[221]. Copyright 2010, Elsevier B.V.; (C) Optical image of a contact lens integrated with amperometric glucose sensor. Reproduced with permission^[222]. Published by Elsevier B.V.; (D) Integrated transparent contact lens capable of transmitting data wirelessly and measuring glucose and Intraocular pressure. Reproduced with permission^[223]. Copyright 2017, The Authors; (E) Schematic representation of a soft, wireless contact lens with integrations of electrochemical glucose sensor and display that serve as feedback indicators. Reproduced with permission^[224]. Copyright 2017, The Authors; (F) Smart contact lenses for continuous glucose monitoring and treatment of diabetic retinopathy. Reproduced with permission^[225]. Copyright 2017, The Authors; (G) A wearable tear-collecting eyeglasses system with a microfluidic electrochemical detector. Reproduced with permission^[226]. Copyright 2019 Elsevier B.V. PDMS: Polydimethylsiloxane; f-DDS: flexible drug deliver system; CE: counter electrode; WE: working electrode; RE: reference electrode.